Curable resin composition, cured product of same and semiconductor device

ABSTRACT

The purpose of the present invention is to provide a curable resin composition which forms a cured product having excellent heat resistance, light resistance, and flexibility. 
     The present invention provides a curable resin composition comprising the following components:
         (A): a polyorganosiloxane represented by the average unit formula: (SiO 4/2 ) a1 (R 1 SiO 3/2 ) a2 (R 1   2 SiO 2/2 ) a3 (R 1   3 SiO 1/2 ) a4  wherein each R 1  is alkyl, aryl, alkenyl, etc., a percentage of the alkyl is 50 to 98 mol %, a percentage of the aryl is 1 to 50 mol %, and a percentage of the alkenyl is 1 to 35 mol % based on the total amount of R 1 , and a1&gt;0, a2&gt;0, a3≥0, a4&gt;0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1;   (B) a polyorganosiloxane represented by the average composition formula:
 
R 2   m H n SiO [(4-m-n)/2] 
 
wherein R 2  is alkyl or aryl, and 0.7≤m≤2.1, 0.001≤n≤1.5, and 0.8≤m+n≤3;
   (C): a zirconium compound; and   (D): a hydrosilylation catalyst.

TECHNICAL FIELD

The present invention relates to a curable resin composition, a cured product thereof, an encapsulating agent using the curable resin composition, and a semiconductor device (in particular, an optical semiconductor device) obtained by using the encapsulating agent to encapsulate a semiconductor element (in particular, an optical semiconductor element). In addition, the present invention also relates to a semiconductor device (in particular, an optical semiconductor device) having a lens obtained by curing the above curable resin composition. The present application claims priority of Japanese Patent Application No. 2016-141874, filed in Japan on Jul. 19, 2016, the content of which is herein incorporated by reference.

BACKGROUND ART

In recent years, optical semiconductor devices have been made to have a higher output and brightness. Then, optical lenses and encapsulants that encapsulate each optical semiconductor element used in such optical semiconductor devices have increasingly been required to have further higher transparency, heat resistance, and light resistance. Meanwhile, electrode corrosion causes a problem such as a decrease in luminous intensity over time, so that excellent gas barrier properties against corrosion gas including, as representative examples, sulfur compounds such as SO_(X) and H₂S have been required at the same time.

As encapsulants for optical semiconductor devices, in particular, for high brightness and high current lighting applications, mainly used are methyl silicone (methyl silicone-based encapsulants) excellent in heat resistance and light resistance (see, for example, Patent Literature 1).

Also, widely used are phenyl silicone-based encapsulants having relatively good gas barrier properties against corrosive gas (see, for example, Patent Literature 2).

CITATION LIST Patent Literature

Patent Literature 1: WO2014/109349

Patent Literature 2: Japanese Patent Laid-Open No. 2004-143361

SUMMARY OF INVENTION Technical Problem

Due to high transparency, heat resistance, and light resistance, the methyl silicone-based encapsulants described in Patent Literature 1 have better barrier properties against corrosive gas than conventional methyl silicone-based encapsulants. However, the properties are still insufficient, so that electrode corrosion cannot be fully prevented.

Here, while the phenyl silicone-based encapsulants described in Patent Literature 2 exhibit increased gas barrier properties and can be used to prevent electrode corrosion in a certain degree, the heat resistance and light resistance thereof are far from those of the methyl silicone-based encapsulants, so that they have not been suited for, in particular, high output and high brightness lighting applications.

In view of such background situations, while the methyl silicone-based encapsulants excellent in heat resistance and light resistance have been used for, in particular, high output and high brightness lighting applications, a step of coating an electrode with a coating liquid before encapsulation so as to prevent corrosion is added and/or gold, which is free of corrosion, is used for the electrode itself. However, the problem is that the manufacturing step is complicated and the cost is high, etc. Meanwhile, usage of the phenyl silicone-based encapsulants having poor heat resistance and light resistance has been limited to applications with low current and low output and low illuminance.

Thus, desired are encapsulants that are used for optical semiconductors and have both increased heat resistance, light resistance and gas barrier properties.

In addition, in recent years, optical semiconductor devices have been made to have a further higher output and brightness. Then, optical lenses and encapsulants that encapsulate each optical semiconductor element in such optical semiconductor devices have increasingly been required to have still higher transparency, heat resistance, light resistance, and gas barrier properties. Under such background situations, for example, a cured product of a methyl silicone resin composition to be used in an optical semiconductor device with high brightness and high current as described in Patent Literature 1 has high heat yellowing resistance and light yellowing resistance. However, it was found that hardness of the cured product is increased due to the influence of heat and light to reduce flexibility, which unavoidably causes cracks of the encapsulant and the light lens.

Accordingly, an object of the present invention is to provide a curable resin composition that can be cured to form a material (cured product) having excellent transparency, heat resistance, light resistance, and flexibility, and in particular a cured product having suppressed transmittance reduction and suppressed hardness rise over time, and maintained flexibility in the high-temperature heat resistance test and the high-brightness light resistance test.

In addition, another object of the present invention is to provide an encapsulating agent using the above curable resin composition and a semiconductor device (in particular, an optical semiconductor device) with excellent quality and durability as obtained by using the encapsulating agent to encapsulate a semiconductor element (in particular, an optical semiconductor element).

Further, another object of the present invention is to provide a lens-forming resin composition using the above curable resin composition and a semiconductor device (in particular, an optical semiconductor device) with excellent quality and durability, which semiconductor device has a lens as obtained by curing the above lens-forming resin composition.

Solution to Problem

The present inventors have conducted intensive studies to solve the above problems and have found out that a curable resin composition containing, as essential components, a polyorganosiloxane having an adjusted structural unit ratio (Q-unit/T-unit), an alkyl group such as a methyl group and an aryl group such as a phenyl group in a molecule, when blended with a zirconium compound, is cured to form a cured product having excellent transparency, heat resistance, light resistance, and flexibility. In particular, in the high-temperature heat resistance test and the high-brightness light resistance test, it has been found that the cured product has suppressed transmittance reduction and suppressed hardness rise over time, and maintained flexibility, thereby completed the present invention.

Specifically, the present invention provides a curable resin composition comprising the following components (A), (B), (C), and (D):

-   -   (A): a polyorganosiloxane represented by the following average         unit formula (I):         (SiO_(4/2))_(a1)(R¹SiO_(3/2))_(a2)(R¹ ₂SiO_(2/2))_(a3)(R¹         ₃SiO_(1/2))_(a4)  (I)         wherein each R¹ is the same or different and is an alkyl group         having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon         atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy         group having 1 to 10 carbon atoms, or a hydroxyl group,     -   when a percentage of the alkyl group is X mol %, a percentage of         the aryl group is Y mol %, and a percentage of the alkenyl group         is Z mol % based on the total amount (100 mol %) of R¹, X is 50         to 98 mol %, Y is 1 to 50 mol %, and Z is 1 to 35 mol %, and     -   a1, a2, a3, and a4 are numbers satisfying a1>0, a2>0, a3≥0,         a4>0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1;     -   (B): a polyorganosiloxane represented by the following average         composition formula (II):         R² _(m)H_(n)SiO_([(4-m-n)/2])  (II)     -   wherein each R² is the same or different and is an alkyl group         having 1 to 10 carbon atoms or an aryl group having 6 to 14         carbon atoms,     -   at least 2 hydrogen atoms are bonded to the silicon atom, and     -   m and n are numbers satisfying 0.7≤m≤2.1, 0.001≤n≤1.5, and         0.8≤m+n≤3;     -   (C): a zirconium compound; and     -   (D): a hydrosilylation catalyst.

In the curable resin composition, the component (A) may be a polyorganosiloxane that has a weight-average molecular weight of not less than 500 and not more than 50000 in terms of polystyrene, has a molecular weight distribution of not less than 1 and not more than 4, and is a liquid or solid having a viscosity at 25° C. of 10 mPa·s or more.

In the component (A) of the curable resin composition, a ratio of X to Y (X/Y) may be 0.5 to 25.

In the curable resin composition, a content of zirconium (in term of metal atom) in the component (C) may be 0.1 to 300 ppm, based on the total amount (10⁶ ppm) of the curable resin composition.

The curable resin composition may further comprise the following component (E):

-   -   (E): a polyorganosiloxysilalkylene having a group containing one         or more aliphatic carbon-carbon unsaturated bonds in a molecule.

The curable resin composition may further comprise the following component (F):

-   -   (F): a silsesquioxane having one or more alkenyl groups and one         or more aryl groups in a molecule.

In the curable resin composition, the component (B) may have at least two structural units represented by (R^(2′) ₂HSiO_(1/2)) where each R^(2′) is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms.

In the curable resin composition, the component (B) may comprise a component (B1) at a content of not less than 1 wt % and not more than 99 wt %, the component (B1) being represented by the following formula (II-1):

[Chem. 1]

-   -   wherein each R²¹ is the same or different and represents an         alkyl group having 1 to 10 carbon atoms or an aryl group having         6 to 14 carbon atoms, and x represents an integer of 0 to 1000,         and     -   the component (B1) being a liquid having a viscosity at 25° C.         of 10000 mPa·s or less.

In the curable resin composition, the component (B) may comprise one kind of polyorganosiloxane represented by the average composition formula (II), or comprise two or more different polyorganosiloxanes represented by the average composition formula (II).

In the curable resin composition, the component (B) may comprise at least one polyorganosiloxane represented by the average composition formula (II) where at least one of R² is an aryl group having 6 to 14 carbon atoms.

The curable resin composition may further comprise a silane coupling agent (G).

In addition, the present invention provides a cured product of the curable resin composition.

The cured product may have a refractive index at 589 nm of not less than 1.46 and not more than 1.54.

In addition, the curable resin composition may be an encapsulating agent.

In addition, the curable resin composition may be a lens-forming resin composition.

Further, the present invention provides a semiconductor device having a semiconductor element and an encapsulant that encapsulates the semiconductor element, wherein the encapsulant is a cured product of the curable resin composition (encapsulating agent).

Furthermore, the present invention provides a semiconductor device having a semiconductor element and a lens, wherein the lens is a cured product of the curable resin composition (lens-forming resin composition).

Moreover, the present invention provides a semiconductor device having a semiconductor element, an encapsulant that encapsulates the semiconductor element, and a lens, wherein the encapsulant is a cured product of the curable resin composition (encapsulating agent) and the lens is a cured product of the curable resin composition (lens-forming resin composition).

In the semiconductor device, the cured product may have a refractive index at 589 nm of not less than 1.46 and not more than 1.54.

The semiconductor device may be an optical semiconductor device.

Advantageous Effects of Invention

Because of the above configurations, the curable resin compositions of the present invention can each be cured to form a cured product having excellent transparency, heat resistance, light resistance and flexibility. In particular, in the high-temperature heat resistance test and the high-brightness light resistance test, the cured product has suppressed transmittance reduction and suppressed hardness rise over time, and maintained flexibility. Because of this, when the above cured products are used, for example, as encapsulants for semiconductor elements and/or lenses in optical semiconductor devices of high brightness and high current lighting applications, high transparency and flexibility can be maintain even after long-term exposure with high-temperature and high-brightness light. This makes it possible to maintain a high luminous intensity for a long period and makes it hard to raise a problem such as lighting failure due to fracture of a bonding wire caused by the occurrence of cracks, thereby remarkably increasing durability of the above optical semiconductor devices. Hence, the curable resin compositions of the present invention may be suitably used as, in particular, materials for forming encapsulant for optical semiconductor elements (LED elements) or optical lens (encapsulating agents or lens-forming resin compositions) in a larger optical semiconductor device having a high output and a high brightness. The optical semiconductor devices obtained by using the curable resin compositions of the present invention as encapsulating agents and/or lens-forming resin compositions have excellent qualities and durability.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1(a) and (b) are schematic diagrams illustrating an embodiment of an optical semiconductor device in which an optical semiconductor element is encapsulated by a cured product of a curable resin composition of the present invention. FIG. 1(a) on the left side is a perspective view; and FIG. 1(b) on the right side is a cross-sectional view.

DESCRIPTION OF EMBODIMENTS

<Curable Resin Composition>

A curable resin composition of the present invention comprises the following components (A), (B), (C), and (D) as essential components:

-   -   (A): a polyorganosiloxane represented by the following average         unit formula (I):         (SiO_(4/2))_(a1)(R¹SiO_(3/2))_(a2)(R¹ ₂SiO_(2/2))_(a3)(R¹         ₃SiO_(1/2))_(a4)  (I)     -   wherein each R¹ is the same or different and is an alkyl group         having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon         atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy         group having 1 to 10 carbon atoms, or a hydroxyl group,     -   when a percentage of the alkyl group is X mol %, a percentage of         the aryl group is Y mol %, and a percentage of the alkenyl group         is Z mol % based on the total amount (100 mol %) of R¹, X is 50         to 98 mol %, Y is 1 to 50 mol %, and Z is 1 to 35 mol %, and     -   a1, a2, a3, and a4 are numbers satisfying a1>0, a2>0, a3≥0,         a4>0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1;     -   (B): a polyorganosiloxane represented by the following average         composition formula (II):         R² _(m)H_(n)SiO_([(4-m-n)/2])  (II)     -   wherein each R² is the same or different and is an alkyl group         having 1 to 10 carbon atoms or an aryl group having 6 to 14         carbon atoms,     -   at least 2 hydrogen atoms are bonded to the silicon atom, and     -   m and n are numbers satisfying 0.7≤m≤2.1, 0.001≤n≤1.5, and         0.8≤m+n≤3;     -   (C): a zirconium compound; and     -   (D): a hydrosilylation catalyst.

This curable resin composition may further comprise, in addition to the above essential components, other components such as a component (E), a component (F), and a silane coupling agent (G) described below.

[Component (A)]

As described above, the component (A), which is an essential component of the curable resin composition of the present invention, is a polyorganosiloxane represented by the following average unit formula (I): (SiO_(4/2))_(a1)(R¹SiO_(3/2))_(a2)(R¹ ₂SiO_(2/2))_(a3)(R¹ ₃SiO_(1/2))_(a4)  (I)

-   -   wherein each R¹ is the same or different and is an alkyl group         having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon         atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy         group having 1 to 10 carbon atoms, or a hydroxyl group,     -   when a percentage of the alkyl group is X mol %, a percentage of         the aryl group is Y mol %, and a percentage of the alkenyl group         is Z mol % based on the total amount (100 mol %) of R¹, X is 50         to 98 mol %, Y is 1 to 50 mol %, and Z is 1 to 35 mol %, and     -   a1, a2, a3, and a4 are numbers satisfying a1>0, a2>0, a3≥0,         a4>0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1.

That is, the component (A) is a polysiloxane having an alkenyl group, and a component capable of making a hydrosilylation reaction with a component having a hydrosilyl group (e.g., the component (B) described below).

Examples of the alkyl group having 1 to 10 carbon atoms represented by R¹ in the above average unit formula (I) include straight-chain or branched-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, an isooctyl group, and a decyl group. Among them, preferred is a methyl group. In addition, the component (A) may have only one kind of the alkyl group or two or more kinds of the alkyl group.

Examples of the aryl group having 6 to 14 carbon atoms represented by R¹ in the above average unit formula (I) include a phenyl group and a naphthyl group. Among them, preferred is a phenyl group. In addition, the component (A) may have only one kind of the aryl group or two or more kinds of the aryl group.

Examples of the alkenyl group having 2 to 8 carbon atoms represented by R¹ in the above average unit formula (I) include substituted or unsubstituted, straight-chain or branched-chain alkenyl groups such as a vinyl group, an allyl group, a butenyl group, a pentenyl group, and a hexenyl group. Examples of the substituent include a halogen atom, a hydroxy group, and a carboxy group. Among them, preferred is a vinyl group. In addition, the component (A) may have only one kind of the alkenyl group or two or more kinds of the alkenyl group.

Examples of the alkoxy group having 1 to 10 carbon atoms of R¹ represented in the above average unit formula (I) include straight-chain or branched-chain alkoxy groups such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, a hexyloxy group, an octyloxy group, an isooctyloxy group, and a decyloxy group. Among them, preferred are a methoxy group and an ethoxy group. In addition, the component (A) may have only one kind of the alkoxy group or two or more kinds of the alkoxy group.

In the component (A), when the percentage of the alkyl group based on the total amount (100 mol %) of R¹ is X mol %, X is 50 to 98 mol %, preferably 55 to 95 mol %, and more preferably 60 to 90 mol %. When X is 50 mol % or more, the curable resin composition of the present invention tends to be cured to give a cured product having excellent heat resistance and light resistance. On the other hand, when X is 98 mol % or less, the resulting cured product tends to have increased gas barrier properties and be less tacky.

In the component (A), when the percentage of the aryl group based on the total amount (100 mol %) of R¹ is Y mol %, Y is 1 to 50 mol %, preferably 3 to 40 mol %, and more preferably 5 to 30 mol %. When Y is 1 mol % or more, the curable resin composition of the present invention tends to be cured to give a less tacky cured product having excellent gas barrier properties. On the other hand, when Y is 50 mol % or less, the resulting cured product tends to have increased heat resistance and light resistance.

In the component (A), when the percentage of the alkenyl group based on the total amount (100 mol %) of R¹ is Z mol %, Z is 1 to 35 mol %, preferably 2 to 25 mol %, and more preferably 3 to 15 mol %. When Z is controlled to within the above ranges, a cured product of the curable resin composition tends to have increased toughness.

The ratio of the alkyl group (X) to the aryl group (Y) (X/Y) in the component (A) is not particularly limited, and preferably 0.5 to 25, more preferably 1 to 20, and still more preferably 2 to 15. When X/Y is controlled to within the above ranges, the curable resin composition of the present invention tends to be cured to give a less tacky cured product having both increased gas barrier properties and excellent heat resistance and light resistance. That is, when X/Y is 0.5 or more, the curable resin composition of the present invention tends to be cured to give a cured product in which heat resistance and light resistance are maintained. Also, setting X/Y to 25 or less tends to give a tack-less cured product while maintaining increased gas barrier properties.

Note that the percentage (mol %) of the alkyl group, the percentage (mol %) of the aryl group, and the percentage (mol %) of the alkenyl group based on the total amount (100 mol %) of R¹ may each be calculated by, for instance, ¹H-NMR spectroscopy.

a1, a2, a3, and a4 in the above average unit formula (I) are numbers satisfying a1>0, a2>0, a3≥0, a4>0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1.

a1 is a positive number (a1>0), corresponding to an existence ratio (in terms of molar ratio) of the Q-unit in the component (A), and is preferably 0.01 to 0.8, more preferably 0.02 to 0.7, and still more preferably 0.03 to 0.6.

a2 is a positive number (a2>0), corresponding to an existence ratio (in terms of molar ratio) of the T-unit in the component (A), and is preferably 0.01 to 0.90, more preferably 0.03 to 0.85, and still more preferably 0.05 to 0.8.

a3 is 0 or a positive number (a3≥0), corresponding to an existence ratio (in terms of molar ratio) of the D-unit in the component (A), and is preferably 0 to 0.9, more preferably 0 to 0.6, and still more preferably 0 to 0.3.

a4 is a positive number (a4>0), corresponds to an existence ratio (in terms of molar ratio) of the M-unit in the component (A), and is preferably 0.01 to 0.9, more preferably 0.03 to 0.8, and still more preferably 0.05 to 0.7.

When a1 to a4 are within the above ranges, the curable resin composition of the present invention tends to be cured to give a much less tacky cured product having both excellent heat resistance and light resistance.

In the above average unit formula (I), a1/a2 corresponds to a ratio of the Q-unit to the T-unit (Q/T; in terms of molar ratio) in the component (A), and is 0.01 to 10, preferably 0.02 to 8, more preferably 0.03 to 6, still more preferably 0.1 to 5, still more preferably 1 to 5, still more preferably 1.5 to 5, and particularly preferably 2 to 5. When a1/a2 is 0.01 or more, a curable resin composition of the present invention tends to be cured to give a cured product having excellent heat resistance and light resistance. Also, setting a1/a2 to 10 or less tends to provide a cured product having excellent flexibility.

X, Y, Z, X/Y, a1 to a4, a1/a2, etc., in the component (A) of the present invention may be suitably adjusted by selecting the kind and composition of each substituent on a silicon atom of an ingredient (the hydrolysable silane compound described below) for forming such structural units during the process described below for producing the component (A).

Examples of the component (A) include materials with partially branched straight-chain, branched-chain, or reticular molecular structures. Note that the component (A) may be used singly or in combinations of two or more. Specifically, two or more components (A) with different molecular structures may be used in combination. For example, a partially branched straight-chain component (A) and a branched-chain component (A) may be used in combination.

The weight-average molecular weight (Mw) of the component (A) is not particularly limited, and preferably not less than 500 and not more than 50000, more preferably not less than 600 and not more than 40000, still more preferably not less than 700 and not more than 20000, and particularly preferably not less than 1000 and not more than 10000. When the weight-average molecular weight is 500 or more, the resulting cured product tends to have increased toughness and be less tacky. Also, when the weight-average molecular weight is 50000 or less, the compatibility with the other components tends to increase. Note that the weight-average molecular weight is calculated by using molecular weights determined by gel permeation chromatography (GPC) in terms of standard polystyrene.

The molecular weight distribution (Mw/Mn) of the component (A) is not particularly limited, and preferably not less than 1 and not more than 4, more preferably 1 to 3.5, still more preferably 1 to 3, and particularly preferably 1 to 2.5. When the molecular weight distribution is 4 or less, the compatibility of the resulting cured product tends to increase. Note that the molecular weight distribution is calculated by using a weight-average molecular weight (Mw) and a number average molecular weight (Mn) as calculated by using molecular weights determined by gel permeation chromatography (GPC) in terms of standard polystyrene.

The component (A) may be a liquid or solid at 25° C. Preferred is a liquid. More specifically, the viscosity at 25° C. of the component (A) is not particularly limited, and preferably 10 mPa·s or higher, more preferably 100 mPa·s or higher, and still more preferably 500 mPa·s or higher. When the viscosity is 10 mPa·s or higher, the curable resin composition tends to be easily prepared and handled. Meanwhile, the upper limit of the viscosity is not particularly limited, and preferably 1000000 mPa·s and more preferably 100000 mPa·s. When the viscosity is 1000000 mPa·s or less, the curable resin composition also tends to be easily prepared and handled. Note that the viscosity at 25° C. may be measured under conditions at a temperature of 25° C. and a rotation number of 20 rpm by using a rheometer (trade name “Physica MCR-302”) manufactured by Anton Paar, Inc., and a parallel plate (with a cone diameter of 25 mm and a taper angle of 0 degrees).

The weight-average molecular weight (Mw), the molecular weight distribution (Mw/Mn), and the viscosity at 25° C. of the component (A) of the present invention may be suitably adjusted by selecting production conditions (e.g., a reaction temperature, a reaction time), the kind and ratio of each group bonded to a silicon atom of an ingredient (the hydrolysable silane compound described below) for forming such structural units during the process described below for producing the component (A).

The component (A) may be produced by a known and conventional process for producing a polysiloxane. Examples of the production process include, but are not particularly limited to, for example, a process comprising subjecting one or two or more hydrolysable silane compounds to hydrolysis and condensation. Provided that for the above hydrolysable silane compounds, a hydrolysable tetrafunctional silane compound (a compound represented by the following formula (a)), a hydrolysable trifunctional silane compound (a compound represented by the following formula (b)), and a hydrolysable monofunctional silane compound (a compound represented by the following formula (d)), which are used to form structural units of the above average unit formula (I), should be used as essential hydrolysable silane compounds. A hydrolysable bifunctional silane compound (a compound represented by the following formula (c)) is optionally used.

More specifically, the component (A) may be produced by, for instance, a process comprising subjecting, to hydrolysis and condensation, a compound of the following formula (a), which is a hydrolysable silane compound for forming a Q-unit, a compound of the following formula (b), which is a hydrolysable silane compound for forming a T-unit, and a compound of the following formula (d), which is a hydrolysable silane compound for forming an M-unit, and optionally a compound of the following formula (c), which is a hydrolysable silane compound for forming a D-unit.

[Chem. 2] Si(X¹)₄  (a) R¹²Si(X²)₃  (b) R¹³ ₂Si(X³)₂  (c) R¹⁴ ₃Si(X⁴)  (d)

The compound of the above formula (a) is a compound used to form a Q-unit in the component (A) of the present invention. In the above formula (a), X¹ represents an alkoxy group or a halogen atom. Examples of the alkoxy group of X¹ include alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an isobutoxy group. Examples of the halogen atom of X¹ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, X¹ is preferably an alkoxy group and more preferably a methoxy group and an ethoxy group. Note that each of four X¹ may be the same or different.

The compound of the above formula (b) is a compound used to form a T-unit in the component (A) of the present invention. In the above formula (b), R¹² is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. Respective examples and preferable aspects of the alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, and alkenyl group having 2 to 8 carbon atoms represented by R¹² are the same as those of R¹ in the above average unit formula (I).

In the above formula (b), X² represents an alkoxy group or a halogen atom. Examples of the alkoxy group of X² include alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an isobutoxy group. In addition, examples of the halogen atom of X² include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, X² is preferably an alkoxy group and more preferably a methoxy group and an ethoxy group. Note that each of three X² may be the same or different.

The compound of the above formula (c) is a compound used to form a D-unit in the component (A) of the present invention. In the formula (c), R¹³ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. Respective examples and preferable aspects of the alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, and alkenyl group having 2 to 8 carbon atoms represented by R¹³ are the same as those of R¹ in the above average unit formula (I). Note that each of two R¹³ may be the same or different.

In the above formula (c), X³ represents an alkoxy group or a halogen atom. Examples of the alkoxy group of X³ include alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an isobutoxy group. In addition, examples of the halogen atom of X³ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, X³ is preferably an alkoxy group and more preferably a methoxy group and an ethoxy group. Note that each of two X³ may be the same or different.

The compound of the above formula (d) is a compound used to form an M-unit in the component (A) of the present invention.

In the formula (d), R¹⁴ is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, or an alkenyl group having 2 to 8 carbon atoms. Respective examples and preferable aspects of the alkyl group having 1 to 10 carbon atoms, aryl group having 6 to 14 carbon atoms, and alkenyl group having 2 to 8 carbon atoms represented by R¹⁴ are the same as those of R¹ in the above average unit formula (I). Note that each of three R¹⁴ may be the same or different.

In the above formula (d), X⁴ represents an alkoxy group, a halogen atom, or a group represented by —OSiR¹⁴ ₃. Examples of the alkoxy group of X⁴ include alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an isobutoxy group. In addition, examples of the halogen atom of X⁴ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, X⁴ is preferably an alkoxy group or a group represented by —OSiR¹⁴ ₃ and more preferably a methoxy group, an ethoxy group, and a group represented by —OSiR¹⁴ ₃. When X⁴ is a group represented by —OSiR¹⁴ ₃, each of three R¹⁴ may be the same or different.

The usage and composition of each hydrolysable silane compound may be suitably adjusted depending on the structure of the desired component (A) of the present invention. For instance, the usage of the compound of the above formula (a) is not particularly limited, and preferably 1 to 80 mol %, more preferably 2 to 70 mol %, and still more preferably 3 to 60 mol %, based on the total amount (100 mol %) of the hydrolysable silane compounds to be used.

In addition, the usage of the compound of the above formula (b) is not particularly limited, and preferably 1 to 90 mol %, more preferably 3 to 85 mol %, and still more preferably 5 to 80 mol %, based on the total amount (100 mol %) of the hydrolysable silane compounds to be used.

In addition, the usage of the compound of the above formula (d) is not particularly limited, and preferably 1 to 90 mol %, more preferably 3 to 80 mol %, and still more preferably 5 to 70 mol %, based on the total amount (100 mol %) of the hydrolysable silane compounds to be used.

In addition, when the compound of the above formula (c) is used, the usage is not particularly limited, and preferably 0 to 90 mol %, more preferably 0 to 60 mol %, and still more preferably 0 to 30 mol %, based on the total amount (100 mol %) of the hydrolysable silane compounds to be used.

Meanwhile, when two or more different hydrolysable silane compounds above are used in combination, these hydrolysable silane compounds may be subjected to hydrolysis and condensation reactions simultaneously or sequentially. If the above reactions are carried out sequentially, the order of the reactions is not particularly limited.

For instance, an aspect can be mentioned in which the compounds of the above formulas (a), (b), and (d) may be subjected to hydrolysis and condensation reactions and the compound of the formula (d) may then be added thereto.

The hydrolysis and condensation reactions of the above hydrolysable silane compounds may be carried out in the presence or absence of a solvent. Of two, it is preferable to carry out the reactions in the presence of a solvent. Examples of the solvent include: aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene; ethers such as diethyl ether, dimethoxy ethane, tetrahydrofuran, dioxane; ketones such as acetone, methylethyl ketone, methylisobutyl ketone; esters such as methyl acetate, ethyl acetate, isopropyl acetate, butyl acetate; amides such as N,N-dimethylformamide, N,N-dimethylacetamide; nitriles such as acetonitrile, propionitrile, benzonitrile; and alcohols such as methanol, ethanol, isopropyl alcohol, and butanol. As the above solvent among them, preferred are ketones and ethers. Note that the solvents may be used singly or in combinations of two or more.

The usage of the solvent is not particularly limited and may be suitably adjusted, depending on a desired reaction time, etc., within the range of 0 to 2000 parts by weight per 100 parts by weight of all the hydrolysable silane compounds.

The hydrolysis and condensation reactions of the above hydrolysable silane compounds may be preferably made to proceed in the presence of a catalyst and water. The catalyst may be an acid catalyst or an alkali catalyst. Examples of the acid catalyst include: mineral acids such as hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, boric acid; phosphates; carboxylic acids such as acetic acid, formic acid, trifluoroacetic acid; sulfonic acids such as methanesulfonic acid, trifluoromethane sulfonic acid, p-toluene sulfonic acid; solid acids such as activated clay; and Lewis acids such as iron chloride. Examples of the alkali acid include: alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, potassium hydroxide, cesium hydroxide; alkali earth metal hydroxides such as magnesium hydroxide, calcium hydroxide, barium hydroxide; alkali metal carbonates such as lithium carbonate, sodium carbonate, potassium carbonate, cesium carbonate; alkali earth metal carbonates such as magnesium carbonate; alkali metal bicarbonates such as lithium bicarbonate, sodium bicarbonate, sodium bicarbonate, potassium bicarbonate, cesium bicarbonate; alkali metal organic acid salts (e.g., acetates) lithium acetate, sodium acetate, potassium acetate, cesium acetate; alkali earth metal organic acid salts (e.g., acetates) such as magnesium acetate; alkali metal alkoxides such as lithium methoxide, sodium methoxide, sodium ethoxide, sodium isopropoxide, potassium ethoxide, potassium t-butoxide; alkali metal phenoxides such as sodium phenoxide; amines (e.g., tertiary amines) such as triethylamine, N-methylpiperidine, 1,8-diazabicyclo[5.4.0]undecane-7-ene, 1,5-diazabicyclo[4.3.0]nonane-5-ene; and nitrogen-containing aromatic heterocyclic compounds such as pyridine, 2,2-bipyridyl, and 1,10-phenanthroline. Note that the catalysts may be used singly or in combinations of two or more. In addition, each catalyst may be used while dissolved or dispersed in water and/or a solvent.

The usage of the catalyst is not particularly limited and may be suitably adjusted within the range of 0.002 to 0.200 mol based on the total amount (1 mol) of all the hydrolysable silane compounds.

The usage of water during the hydrolysis and condensation reactions is not particularly limited and may be suitably adjusted within the range of 0.5 to 20 mol based on the total amount (1 mol) of all the hydrolysable silane compounds.

The water addition procedure is not particularly limited and all amount of water used (the total usage) may be added as one portion or sequentially. When sequentially added, the water may be added continuously or intermittently.

When the hydrolysis and condensation reactions of the above hydrolysable silane compounds are carried out, the reaction conditions are preferably selected such that the weight-average molecular weight (Mw), the molecular weight distribution (Mw/Mn), and the viscosity at 25° C., etc., of the component (A) of the present invention are within the predetermined ranges. The reaction temperature during the hydrolysis and condensation reactions is not particularly limited, and preferably −10 to 100° C. and more preferably 0 to 80° C. When the reaction temperature is controlled to within the above ranges, the weight-average molecular weight (Mw), the molecular weight distribution (Mw/Mn), and the viscosity at 25° C., etc., of the component (A) tend to be controlled within the predetermined ranges. The reaction time of the hydrolysis and condensation reactions is not particularly limited, and preferably 0.1 to 24 h and more preferably 1.5 to 18 h. The above hydrolysis and condensation reactions may be carried out under ordinary pressure or carried out under increased or reduced pressure. Note that examples of the atmosphere during the hydrolysis and condensation reactions include, but are not particularly limited to, inert gas atmospheres such as a nitrogen atmosphere and an argon atmosphere. The reactions may also be performed in the presence of oxygen such as air, etc., but the reactions are preferably performed under an inert gas atmosphere.

The hydrolysis and condensation reactions of the above hydrolysable silane compounds are carried out to give a component (A) of the present invention. The component (A) of the present invention may be separated and purified by separation means such as water washing, acid washing, alkali water washing, filtration, concentration, distillation, extraction, crystallization, recrystallization, and chromatography, and combinations thereof.

Because the component (A) of the present invention has the above configurations, the curable resin compositions containing the component (A) as an essential component can be cured to form a less tacky cured product having both excellent heat resistance and light resistance.

Note that in the present curable resin composition, the components (A) may be used singly or in combinations of two or more.

When two or more components (A) are used in combination, X, Y, Z, X/Y, a1 to a4, a1/a2, etc., may each be an average as calculated in accordance with the blending ratio between the respective components (A).

The content (amount blended) of the component (A) in the curable resin composition of the present invention is not particularly limited and preferably 20 to 99 wt %, more preferably 40 to 97 wt %, and still more preferably 50 to 95 wt %, based on the total amount (100 wt %) of the curable resin composition. When the content is adjusted to 20 wt % or more, the resulting cured product tends to have further improved and excellent heat resistance and light resistance.

[Component (B)]

The component (B), which is an essential component of the curable resin composition of the present invention, is a polyorganosiloxane represented by the following average composition formula (II): R² _(m)H_(n)SiO_([(4-m-n)/2])  (II)

-   -   wherein each R² is the same or different and is an alkyl group         having 1 to 10 carbon atoms or an aryl group having 6 to 14         carbon atoms, at least 2 hydrogen atoms are bonded to the         silicon atom, and m and n are numbers satisfying 0.7≤m≤2.1,         0.001≤n≤1.5, and 0.8≤m+n≤3.

That is, the component (B) is a component that is a polyorganosiloxane with a hydrosilyl group, and a component capable of making a hydrosilylation reaction with a component with an alkenyl group (e.g., the component (A), the component (E) described below and the component (F) described below).

Examples of the alkyl group having 1 to 10 carbon atoms represented by R² in the above average composition formula (II) include straight-chain or branched-chain alkyl groups such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, an isooctyl group, and a decyl group. Among them, preferred is a methyl group. In addition, the component (B) may have only one kind of the alkyl group or two or more kinds of the alkyl group.

Examples of the aryl group having 6 to 14 carbon atoms represented by R² in the above average composition formula (II) include a phenyl group and a naphthyl group. Among them, preferred is a phenyl group. In addition, the component (B) may have only one kind of the aryl group or two or more kinds of the aryl group.

In the component (B), when the percentage of the alkyl group based on the total amount (100 mol %) of R² is X′ mol %, X′ is not particularly limited, and preferably 20 to 95 mol %, more preferably 30 to 93 mol %, and still more preferably 40 to 90 mol %. When X′ is 20 mol % or more, a curable resin composition of the present invention tends to be cured to give a cured product having excellent heat resistance and light resistance. Also, when X′ is 95 mol % or less, the resulting cured product tends to have increased gas barrier properties.

In the component (B), when the percentage of the aryl group based on the total amount (100 mol %) of R² is Y′ mol %, Y′ is not particularly limited, and preferably 1 to 80 mol %, more preferably 3 to 60 mol %, and still more preferably 5 to 40 mol %. When Y′ is 1 mol % or more, the resulting cured product tends to have increased gas barrier properties and be less tacky. Also, when Y′ is 80 mol % or less, the resulting cured product tends to have increased heat resistance and light resistance.

In the component (B), when the percentage of the SiH group (hydrosilyl group) based on the total amount (100 mol %) of R² is Z′ mol %, Z′ is not particularly limited, and preferably 2 to 70 mol %, more preferably 5 to 60 mol %, and still more preferably 10 to 55 mol %. When Z′ is adjusted to within the above ranges, the curable resin composition tends to have increased curing performance.

The ratio of the alkyl group content (X′) to the aryl group content (Y′) (X′/Y′) in the component (B) is not particularly limited, and preferably 1/100 to 100/1, more preferably 10/100 to 100/10, and still more preferably 20/100 to 100/20. When X′/Y′ is adjusted to within the above ranges, the curable resin composition of the present invention tends to be cured to give a less tacky cured product having both increased gas barrier properties and excellent heat resistance and light resistance. That is, when X′/Y′ is 1/100 or more, a curable resin composition of the present invention tends to be cured to give a cured product in which heat resistance and light resistance are maintained. Also, setting X′/Y′ to 100/1 or less tends to give a tack-less cured product while maintaining increased gas barrier properties.

Note that the percentage (mol %) of the alkyl group, the percentage (mol %) of the aryl group content, and the percentage (mol %) of the SiH group based on the total amount (100 mol %) of R² may each be calculated by, for instance, ¹H-NMR spectroscopy.

In the above average composition formula (II), m and n are numbers satisfying 0.7≤m≤2.1, 0.001≤n≤1.5, and 0.8≤m+n≤3.

m represents an average number of R² per silicon atom in the component (B), is selected from the range of 0.7 to 2.1, and is preferably 0.8 to 2.1 and more preferably 1 to 2.

n represents the number of silicon-bonded hydrogen atoms per silicon atom in the component (B), is selected from the range of 0.001 to 1.5, and is preferably 0.01 to 1.2 and more preferably 0.2 to 1.

m+n represents an average number of the sum of R² and silicon-bonded hydrogen atoms per silicon atom in the component (B), is selected from the range of 0.8 to 3, and is preferably 1 to 2.9 and more preferably 1.5 to 2.8.

When m and n satisfy the above conditions, the curable resin composition of the present invention tends to be cured to give a less tacky cured product having both excellent heat resistance and light resistance.

X′, Y′, Z′, X′/Y′, m, n, m+n, etc., in the component (B) of the present invention may be suitably adjusted by selecting the kind and composition of each group bonded to a silicon atom of an ingredient (a hydrolysable silane compound) for forming such structural units during the process described below for producing the component (B).

Preferably, the component (B) has at least two structural units (M-units) represented by (R^(2′) ₂HSiO_(1/2)) in a molecule. Specifically, it is preferable that the component (B) has a structure in which at least two ends are ended by the M-units represented by (R^(2′) ₂HSiO_(1/2)). Each R^(2′) in the M-unit is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms. The alkyl group having 1 to 10 carbon atoms and the aryl group having 6 to 14 carbon atoms of R^(2′) are the same as those of R² in the above average composition formula (II). Preferred is an alkyl group having 1 to 10 carbon atoms. More preferred is a methyl group.

When the component (B) has such a structure with at least two ends having SiH groups (hydrosilyl groups), the curable resin composition tends to be cured to give a cured product having excellent flexibility, heat resistance, and light resistance.

When the component (B) has M-units represented by (R^(2′) ₂HSiO_(1/2)), the number of the M-units is not particularly limited as long as the number is 2 or more and is preferably 2 to 4 and more preferably 2. The two or more M-units represented by (R^(2′) ₂HSiO_(1/2)) may be the same or different.

In addition, the component (B) may have, in addition to the M-units represented by (R^(2′) ₂HSiO_(1/2)), an SiH group(s) on its side chain(s).

Examples of the component (B) include materials with straight-chain, partially branched straight-chain, branched-chain, or reticular molecular structures. Note that the component (B) may be used singly or in combinations of two or more. Specifically, two or more components (B) with different molecular structures may be used in combination. For example, a straight-chain component (B) and a branched-chain component (B) may be used in combination.

The form of component (B) may be a liquid or solid. Of two, preferred is a liquid of which the viscosity at 25° C. is more preferably 0.1 to 100000 mPa·s. The viscosity at 25° C. of the component (B) may be measured by the same method as for the above component (A).

An example of the component (B) includes a polyorganosiloxane that is represented by the following average unit formula: (R^(2a)SiO_(3/2))_(c1)(R^(2a) ₂SiO_(2/2))_(c2)(R^(2a) ₃SiO_(1/2))_(c3)(SiO_(4/2))_(c4)(X⁵O_(1/2))_(c5) and preferably has at least two structural units (M-units) represented by (R^(2a) ₂HSiO_(1/2)). Each R^(2a) in the average unit formula and the M-units is the same or different and is a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, or an aryl group having 6 to 14 carbon atoms. Respective examples and preferable aspects of the alkyl group having 1 to 10 carbon atoms and aryl group having 6 to 14 carbon atoms represented by R^(2a) are the same as those of R² in the above average composition formula (II).

Some of R^(2a) may be a hydrogen atom (a hydrogen atom constituting a hydrosilyl group). The percentage of the hydrogen atom based on the total amount (100 mol %) of R^(2a) is not particularly limited, and preferably 1 to 70 mol %. When the percentage of the hydrogen atom is controlled to within the above range, the curable resin composition tends to have increased curing performance.

In the above average unit formula, X⁵ is a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Particularly preferred is a methyl group.

In the above average unit formula, c1 is 0 or a positive number, c2 is 0 or a positive number, c3 is 0 or a positive number, c4 is 0 or a positive number, c5 is 0 or a positive number, and (c1+c2+c3) is a positive number.

Preferable examples of the component (B) include a straight-chain polyorganosiloxane having two or more hydrosilyl groups at both ends of the molecule.

The percentage of the hydrogen atom (silicon-bonded hydrogen atom) based on the total amount (100 mol %) of groups bonded to the silicon atoms in the straight-chain polyorganosiloxane is preferably 1 to 70 mol %. The percentage of the alkyl group (in particular, the methyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is preferably 20 to 95 mol %. The percentage of the aryl group (in particular, the phenyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is preferably 1 to 80 mol %. When the above straight-chain polyorganosiloxane, where the percentage of the alkyl group (in particular, the methyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 20 mol % or more (e.g., 40 to 95 mol %), is used, the resulting cured product tends to have increased heat resistance.

Note that the percentage (mol %) of each of the alkyl group, the aryl group, and the hydrogen atom based on the total amount (100 mol %) of groups bonded to the silicon atoms may be calculated by, for instance, ¹H-NMR spectroscopy.

Preferable examples of the straight-chain polyorganosiloxane include a polyorganosiloxane represented by the following formula (II-1) (hereinafter sometimes referred to as a component (B1)).

[Chem. 3]

-   -   wherein each R²¹ is the same or different and represents an         alkyl group having 1 to 10 carbon atoms or an aryl group having         6 to 14 carbon atoms, and x represents an integer of 0 to 1000.

Respective examples and preferable aspects of the alkyl group having 1 to 10 carbon atoms and aryl group having 6 to 14 carbon atoms of R²¹ are the same as those of R² in the above average composition formula (II).

x represents an integer of 0 to 1000. Preferred is an integer of 1 to 100.

The component (B) contains the component (B1) at a content of preferably not less than 1 wt % and not more than 99 wt %, more preferably not less than 10 wt % and not more than 50 wt %.

The component (B1) may be a liquid or solid at 25° C. Preferred is a liquid. The viscosity at 25° C. of the component (B1) is not particularly limited, and preferably 10000 mPa·s or less and more preferably 5000 mPa·s or less. When the viscosity is 10000 mPa·s or less, the compatibility of the resulting cured product tends to increase more. Meanwhile, the lower limit of the viscosity is not particularly limited, and preferably 1 mPa·s and more preferably 5 mPa·s. When the viscosity is 1 mPa·s or higher, the curable resin composition tends to be prepared and handled easily. Note that the viscosity at 25° C. may be measured by using substantially the same conditions as for the component (A).

Another example of the component (B) includes a branched-chain polyorganosiloxane having two or more M-units represented by (R₂HSiO_(1/2)) and a siloxane unit (T-unit) represented by RSiO_(3/2) in a molecule. Like R² in the above average composition formula (II), each R is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms.

The percentage of the alkyl group (in particular, the methyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms in the branched-chain polyorganosiloxane is preferably 20 to 95 mol %. The percentage of the aryl group (in particular, the phenyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is preferably 1 to 80 mol %. In addition, when the above branched-chain polyorganosiloxane, where the percentage of the alkyl group (in particular, the methyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 20 mol % or more (e.g., 50 to 90 mol %), is used, the resulting cured product tends to have increased heat resistance.

The branched-chain polyorganosiloxane may be represented by, for example, the above average unit formula where c1 is a positive number. In this case, it is preferable that c2/c1 is a number of 0 to 10, c3/c1 is a number of 0 to 0.5, c4/(c1+c2+c3+c4) is a number of 0 to 0.3, and c5/(c1+c2+c3+c4) is a number of 0 to 0.4. In addition, the molecular weight, namely the weight-average molecular weight of the branched-chain polyorganosiloxane as measured by GPC in terms of standard polystyrene is preferably 100 to 50000, and more preferably 150 to 40000.

The weight-average molecular weight (Mw) of the component (B) is not particularly limited, and preferably not less than 100 and not more than 50000, more preferably not less than 150 and not more than 40000, still preferably not less than 175 and not more than 20000, and particularly preferably not less than 200 and not more than 10000. When the weight-average molecular weight is 100 or more, the resulting cured product has increased toughness and is likely to be less tacky. On the other hand, when the weight-average molecular weight is 50000 or less, the compatibility with the other components tends to increase. Note that the weight-average molecular weight is calculated by using molecular weights determined by gel permeation chromatography (GPC) in terms of standard polystyrene.

The molecular weight distribution (Mw/Mn) of the component (B) is not particularly limited, and preferably not less than 1 and not more than 4, more preferably 1 to 3.5, still more preferably 1 to 3, and particularly preferably 1 to 2.5. When the molecular weight distribution is 4 or less, the compatibility of the resulting cured product tends to increase. Note that the molecular weight distribution may be calculated by using a weight-average molecular weight (Mw) and a number average molecular weight (Mn) as calculated by using molecular weights determined by gel permeation chromatography (GPC) in terms of standard polystyrene.

The component (B) may be a liquid or solid at 25° C. Preferred is a liquid. The viscosity at 25° C. of the component (B) is not particularly limited, and preferably 1 mPa·s or higher and more preferably 5 mPa·s or higher. When the viscosity is 1 mPa·s or higher, the curable resin composition tends to be prepared and handled easily. Meanwhile, the upper limit of the viscosity is not particularly limited, and preferably 10000 mPa·s and more preferably 5000 mPa·s. When the viscosity is 10000 mPa·s or less, the compatibility tends to become better. Note that the viscosity at 25° C. may be measured by using substantially the same conditions as for the component (A).

The component (B) may be produced by a known and conventional process for producing a polysiloxane and is not particularly limited. Specifically, the component (B) can be produced by a process comprising subjecting one or two or more hydrolysable silane compounds to hydrolysis and condensation in the same manner as the above process for producing the component (A) except for using, as starting materials, hydrolysable silane compounds where the alkenyl groups having 2 to 8 carbon atoms of R¹², R¹³, and R¹⁴ are replaced by hydrogen atoms in the hydrolysable silane compounds represented by the formulas (b), (c), and (d) that are used in the above process for producing the component (A).

In addition, when the component (B) has an M-unit with a terminal SiH, the component (B) can be produced by a process comprising subjecting one or two or more hydrolysable silane compounds to hydrolysis and condensation in the same manner as the above process for producing the component (A) except for further using, as additional starting materials, a hydrolysable silane compound represented by the following formula (e) for forming the M-unit.

[Chem. 4] R²² ₂HSi(X⁶)  (e)

The compound of the above formula (e) is a compound used to form an M-unit with a terminal SiH group in the component (B) of the present invention. In the formula (e), R²² is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms. Respective examples and preferable aspects of the alkyl group having 1 to 10 carbon atoms and aryl group having 6 to 14 carbon atoms represented by R²² are the same as those of R² in the above average composition formula (II). Note that each of two R²² may be the same or different.

In the above formula (e), X⁶ represents an alkoxy group, a halogen atom, or a group represented by —OSiR²² ₂. Examples of the alkoxy group of X⁶ include alkoxy groups having 1 to 10 carbon atoms such as a methoxy group, an ethoxy group, a propoxy group, an isopropoxy group, a butoxy group, and an isobutoxy group. In addition, examples of the halogen atom of X⁶ include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Among them, X⁶ is preferably an alkoxy group or a group represented by —OSiR²² ₂ and more preferably a methoxy group, an ethoxy group, and a group represented by —OSiR²² ₂. When X⁶ is a group represented by —OSiR²² ₂, each of two R²² may be the same or different.

Preferable specific examples of the component (B) of the present invention include 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,3,3,5,5,7,7,7-octamethyltetrasiloxane, and 1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane. Manufactured articles containing the component (B) such as trade names “HMS-031”, “HPM-502”, “HMS-991”, “DMS-H03”, “DMS-H11”, “DMS-H21”, 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane (each manufactured by Gelest, Inc.); and 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane (manufactured by NANJING SiSiB Silicones, Inc.) are available.

Because the component (B) of the present invention has the above configurations, curable resin compositions containing the component (B) as an essential component can each be cured to form a less tacky cured product having both excellent heat resistance and light resistance.

The curable resin composition of the present invention, as the components (B), may contain one kind of polyorganosiloxane represented by the average composition formula (II) alone, or two or more different polyorganosiloxanes represented by the average composition formula (II). The components (B) preferably contains at least one polyorganosiloxane represented by the average composition formula (II) wherein at least one of R² is an aryl group having 6 to 14 carbon atoms.

When two or more components (B) are used in combination, X′, Y′, Z′, X′/Y′, m, n, m+n, c1 to c5, x, etc., may each be an average as calculated in accordance with the blending ratio between the respective components (B).

The content (amount blended) of the component (B) in the curable resin composition of the present invention is not particularly limited and preferably 5 to 50 wt %, more preferably 7 to 30 wt %, and still more preferably 10 to 25 wt %, based on the total amount (100 wt %) of the curable resin composition. When the content is adjusted to 5 wt % or more, the resulting cured product tends to have further improved heat resistance and light resistance.

The content (amount blended) of the component (B) based on the component (A) in the curable resin composition of the present invention is not particularly limited and, per 100 parts by weight of the component (A), preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight, and still more preferably 10 to 50 parts by weight. When the content is adjusted to 1 part by weight or more, the resulting cured product tends to have further improved heat resistance and light resistance.

[Component (C)]

As described above, the component (C) which is an essential component of the curable resin composition of the present invention is a zirconium compound. The curable resin composition of the present invention, when containing the component (C), gives a cured product unlikely to have decreased flexibility due to hardness rise, decreased weight, and decreased transparency, for example, even after long-term exposure with high-temperature and high-brightness light.

Examples of the component (C) may include an organic salt of zirconium, a zirconium alkoxide, a complex (complex salt) of zirconium, an inorganic salt of zirconium, and the like.

Examples of the organic salt of zirconium include an organic salt, and a compound formed by replacing at least one hydrogen atom of an inorganic salt with a monovalent organic group (for example, a monovalent substituted or unsubstituted hydrocarbon group described below). Examples of the organic salt include an organic carboxylic acid salt (for example, acetate, propionate, butyrate, isobutyrate, valerate, isovalerate, caproate, heptanoate, octanoate, isooctanoate, 2-ethylhexanoate, stearate, and the like), and the like. Examples of the inorganic salt include an oxo acid salt of a carbon atom (for example, carbonate and the like), an oxo acid salt of a sulfur atom (for example, sulfate and the like), an oxo acid salt of nitrogen atom (for example, nitrate and the like), oxo acid salt of phosphorus atom (for example, phosphate and the like), oxo acid salt of chlorine atom (for example, perchlorate and the like).

As a carboxylic acid constituting the organic carboxylic acid salt of zirconium, known or canventional carboxylic acids can be used. Among these, carboxylic acids having 1 to 20 (preferably 2 to 15, more preferably 4 to 12, still more preferably 5 to 10) carbon atoms are preferable, and carboxylic acids having 8 carbon atoms such as 2-ethylhexanoic acid are more preferable. In particular, the carboxylic acid salt of zirconium is preferably zirconium carboxylate having 1 to 20 carbon atoms, more preferably zirconium 2-ethylhexanoate.

Examples of the zirconium alkoxide include zirconium alkoxides constituting of zirconium and an alcohol having 1 to 20 carbon atoms (preferably 1 to 6 carbon atoms), such as zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, and the like.

Examples of the zirconium complex (complex salt) include acetylacetonate, triflate, pyridine complex, bipyridyl complex, terpyridyl complex, pincer complex, imine complex, salen complex, tetramethylenediamine complex, ethylenediamine complex, ephedrine complex, carbonyl complex, dienyl complex of zirconium or zirconium alkoxide, and the like.

Specific examples of the zirconium complex (complex salts) include zirconium tetraacetylacetonate, zirconium tributoxyacetylacetonate, zirconium dibutoxydiacetylacetonate, and the like.

Examples of the inorganic salt of zirconium include zirconium halide (for example, zirconium fluoride, zirconium chloride, zirconium bromide, zirconium iodide), zirconium oxyhalide (for example, zirconium oxyfluoride, zirconium oxychloride, zirconium oxybromide, zirconium oxyiodide), zirconium nitrate, zirconium sulfate, and the like.

Manufactured articles containing the component (C) such as trade name “Octope Zr” (manufactured by Hope Chemical Co., Ltd.), trade name “ZAA” (manufactured by Nippon Soda Co., Ltd.) are commercially available.

Note that in the present curable resin composition, the component (C) may be used singly or in combinations of two or more.

The content of zirconium (in term of metal atom) in the component (C) in the curable resin composition of the present invention is not particularly limited and preferably 0.1 to 300 ppm, more preferably 0.5 to 250 ppm, still more preferably 1 to 200 ppm, based on the total amount (10⁶ ppm) of the curable resin composition. When the content is adjusted to 0.1 ppm or more, the resulting cured product tends to be unlikely to have decreased flexibility due to hardness rise, decreased weight, and decreased transparency. When the content is adjusted to 300 ppm or lower, the resulting cured product tends to have further improved transparency. The content of zirconium metal atoms in the curable resin composition is measured by ICP-MS (inductively coupled plasma mass spectrometry).

The content of zirconium (in term of metal atom) in the component (C) in the curable resin composition of the present invention is not particularly limited and preferably 0.1 to 450 ppm, more preferably 0.5 to 400 ppm, still more preferably 1 to 350 ppm, based on the total amount (10⁶ ppm) of the component (A) and the component (B). When the content is adjusted to 0.1 ppm or more, the resulting cured product tends to be unlikely to have decreased flexibility due to hardness rise, decreased weight, and decreased transparency. When the content is adjusted to 300 ppm or lower, the resulting cured product tends to have further improved transparency. The content of zirconium metal atoms in the curable resin composition is measured by ICP-MS (inductively coupled plasma mass spectrometry).

The content of the component (C) in the curable resin composition of the present invention is not particularly limited and preferably 0.5 to 1800 ppm, more preferably 1 to 1600 ppm, still more preferably 3 to 1400 ppm, based on the total amount (10⁶ ppm) of the curable resin composition. In particular, when the content of zirconium metal atoms is within the above range and the amount of component (C) is within the above range, the resulting cured product is still more unlikely to have decreased flexibility due to hardness rise, decreased weight, and decreased transparency.

[Component (D)]

As described above, the component (D) which is an essential component of the curable resin composition of the present invention is a hydrosilylation catalyst. When the curable resin composition of the present invention containing a hydrosilylation catalyst is heated, a hydrosilylation reaction between an aliphatic carbon-carbon double bond (in particular, an alkenyl group) and a hydrosilyl group in the curable resin composition tends to proceed more efficiently.

Examples of the hydrosilylation catalyst include well-known hydrosilylation catalysts such as platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts. Specific examples include: platinum-based catalysts such as platinum fine powder, platinum black, platinum-supporting silica fine powder, platinum-supporting activated carbon, chloroplatinic acid, complexes of chloroplatinic acid and an alcohol, aldehyde, or ketone, olefin complexes of platinum, carbonyl complexes of platinum such as a platinum-carbonyl vinylmethyl complex, platinum-vinylmethyl siloxane complexes such as a platinum-divinyltetramethyldisiloxane complex and a platinum-cyclovinylmethylsiloxane complex, platinum-phosphine complexes, and platinum-phosphite complexes; and palladium-based catalysts or rhodium-based catalysts in which a palladium atom or a rhodium atom instead of the platinum atom is included in each of the above platinum-based catalysts. Among them, the hydrosilylation catalyst is preferably a platinum-vinylmethylsiloxane complex, a platinum-carbonyl vinylmethyl complex, and complexes of chloroplatinic acid and an alcohol or aldehyde because the reaction rate is good.

Note that in the present curable resin composition, the hydrosilylation catalysts may be used singly or in combinations of two or more.

The content (amount blended) of the hydrosilylation catalyst based on the total amount (1 mol) of aliphatic carbon-carbon double bonds (in particular, alkenyl groups) contained in the curable resin composition of the present invention is preferably 1×10⁻⁸ to 1×10⁻² mol and more preferably 1×10⁻⁶ to 1×10⁻³ mol. When the content is 1×10⁻⁸ mol or more, the resulting cured product tends to be formed more efficiently. Also, when the content is 1×10⁻² mol or less, the resulting cured product excellent in hues (i.e., a less colored product) tends to be obtained.

The content (amount blended) of the hydrosilylation catalyst in the curable resin composition of the present invention, an amount by weight of the platinum, palladium, or rhodium in the hydrosilylation catalyst is preferably an amount within a range of 0.01 to 1000 ppm and more preferably an amount within a range of 0.1 to 500 ppm. If the hydrosilylation catalyst content is within such ranges, the resulting cured product with more excellent hue tends to be obtained more efficiently.

[Component (E)]

A curable resin composition of the present invention may comprise a polyorganosiloxysilalkylene having a group containing one or more aliphatic carbon-carbon unsaturated bonds in a molecule (sometimes simply referred to as a “component (E)”). That is, the component (E) is a polysiloxane with a group containing an aliphatic carbon-carbon unsaturated bond such as an alkenyl group, and is a component capable of making a hydrosilylation reaction with a component with a hydrosilyl group (e.g., the above-described component (B)).

The component (E) is a polyorganosiloxane having a group containing one or more aliphatic carbon-carbon unsaturated bonds in a molecule and containing, as a main chain, a siloxane bond (—Si—O—Si—) and a bond represented by (where R^(A) represents a divalent hydrocarbon group; hereinafter referred to as a “silalkylene bond”). That is, polyorganosiloxane having no any silalkylene bond such as the above component (A) is not included in the component (E). When the curable resin composition of the present invention contains such a component (E), the resulting cured product has a decreased surface tack and it is possible to form a cured product which is unlikely to be yellowed.

Examples of the divalent hydrocarbon group (R^(A)) in the silalkylene bond contained in a molecule of component (E) include: straight-chain or branched-chain alkylene groups (e.g., a group represented by —[CH₂]_(t)—, where t represents an integer of 1 or more); and divalent alicyclic hydrocarbon groups. Examples of the straight-chain or branched-chain alkylene groups include straight-chain or branched-chain alkylene groups having 1 to 18 carbon atoms such as a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, and a trimethylene group. Examples of the divalent alicyclic hydrocarbon groups include divalent cycloalkylene groups (including cycloalkylidene groups) such as a 1,2-cyclopentylene group, a 1,3-cyclopentylene group, a cyclopentylidene group, a 1,2-cyclohexylene group, a 1,3-cyclohexylene group, a 1,4-cyclohexylene group, and a cyclohexylidene group. Among them, R^(A) is preferably straight-chain or branched-chain alkylene groups and particularly preferably an ethylene group.

When compared with the component (A), the component (E) hardly produces a low-molecular-weight ring during the production steps and also hardly produces a silanol group (—SiOH) when decomposed by heating, etc. Thus, when the component (E) is used, a cured product of the curable resin composition tends to have decreased surface tack and is unlikely to be yellowed.

Examples of the component (E) include materials with straight-chain, partially branched straight-chain, branched-chain, or reticular molecular structures. Note that the component (E) may be used singly or in combinations of two or more. Specifically, two or more components (E) with different molecular structures may be used in combination. For example, a straight-chain component (E) and a branched-chain component (E) may be used in combination.

Examples of the group containing an aliphatic carbon-carbon unsaturated bond, which is contained in the molecule of component (E), include: C₂₋₂₀ alkenyl groups (preferably C₂₋₁₀ alkenyl groups, more preferably C₂₋₈ alkenyl groups) such as a vinyl group, an allyl group, a methallyl group, a 1-pentenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 5-hexenyl group; C₃₋₁₂ cycloalkenyl groups such as a cyclohexenyl group; C₄₋₁₅ crosslinked cyclic unsaturated hydrocarbon groups such as a bicycloheptenyl group; C₂₋₄ alkenyl-substituted aryl groups such as a styryl group; and cinnamyl groups. Among them, preferred are alkenyl groups, more preferred are C₂₋₈ alkenyl groups, and still more preferred is a vinyl group. In addition, the component (E) may have only one kind of a group containing an aliphatic carbon-carbon unsaturated bond or two or more kinds of a group containing an aliphatic carbon-carbon unsaturated bond. The group containing an aliphatic carbon-carbon unsaturated bond of the component (E) is preferably a group that is bonded to a silicon atom.

Examples of a group bonded to the silicon atom other than the groups containing an aliphatic carbon-carbon unsaturated bond of the component (E) include a hydrogen atom, a monovalent hydrocarbon group, and a monovalent heterocyclic group.

Examples of the monovalent hydrocarbon group include: monovalent aliphatic hydrocarbon groups; monovalent alicyclic hydrocarbon groups; monovalent aromatic hydrocarbon groups; and monovalent groups in which at least two of an aliphatic hydrocarbon group, an alicyclic hydrocarbon group, and an aromatic hydrocarbon group are bonded. Examples of the monovalent heterocyclic group include a pyridyl group, a furyl group, and a thienyl group.

Examples of the monovalent aliphatic hydrocarbon group include an alkyl group, an alkenyl group, and an alkynyl group. Examples of the alkyl group include straight-chain or branched-chain C₁₋₂₀ alkyl groups (preferably C₁₋₁₀ alkyl groups, more preferably C₁₋₄ alkyl groups) such as a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, an isooctyl group, a decyl group, and a dodecyl group. Examples of the alkenyl group include C₂₋₂₀ alkenyl groups (preferably C₂₋₁₀ alkenyl groups, more preferably C₂₋₄ alkenyl groups) such as a vinyl group, an allyl group, a methallyl group, a 1-propenyl group, an isopropenyl group, a 1-butenyl group, a 2-butenyl group, a 3-butenyl group, a 1-pentenyl group, a 2-pentenyl group, a 3-pentenyl group, a 4-pentenyl group, a 5-hexenyl group. Examples of the alkynyl group include C₂₋₂₀ alkynyl groups (preferably C₂₋₁₀ alkynyl groups, more preferably C₂₋₄ alkynyl groups) such as an ethynyl group and a propynyl group.

Examples of the monovalent alicyclic hydrocarbon group include: C₃₋₁₂ cycloalkyl groups such as a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cyclododecyl group; C₃₋₁₂ cycloalkenyl groups such as a cyclohexenyl group; and C₄₋₁₅ crosslinked cyclic hydrocarbon groups such as a bicycloheptanyl group and a bicycloheptenyl group.

Examples of the monovalent aromatic hydrocarbon group include: C₆₋₁₄ aryl groups (in particular, C₆₋₁₀ aryl groups) such as a phenyl group, a naphthyl group, and an anthryl group.

In addition, examples of the group in which an aliphatic hydrocarbon group and an alicyclic hydrocarbon group are bonded include a cyclohexylmethyl group and a methylcyclohexyl group. Examples of the group in which an aliphatic hydrocarbon group and an aromatic hydrocarbon group are bonded include: C₇₋₁₈ aralkyl groups (in particular, C₇₋₁₀ aralkyl groups) such as a benzyl group, a phenethyl group; C₆₋₁₀ aryl-C₂₋₆ alkenyl groups such as a cinnamyl group; C₁₋₄ alkyl-substituted aryl groups such as a tolyl group; and C₂₋₄ alkenyl-substituted aryl groups such as a styryl group.

The above monovalent hydrocarbon groups may each have a substituent. Specifically, each monovalent hydrocarbon group exemplified above may be a monovalent hydrocarbon group, at least one hydrogen atom of which is replaced by a substituent. The number of carbon atoms of the substituent is preferably 0 to 20 and more preferably 0 to 10. Specific examples of the substituent include: a halogen atom; a hydroxyl group; an alkoxy group; an alkenyloxy group; an aryloxy group; an aralkyloxy group; an acyloxy group; a mercapto group; an alkylthio group; an alkenylthio group; an arylthio group; an aralkylthio group; a carboxyl group; an alkoxycarbonyl group; an aryloxycarbonyl group; an aralkyloxycarbonyl group; an amino group; a mono- or dialkylamino group; a mono- or diphenylamino group; an acylamino group; an epoxy-containing group; an oxetanyl-containing group; an acyl group; an oxo group; an isocyanate group; and a group in which two or more of the above are bonded via a C₁₋₆ alkylene group.

Examples of the alkoxy group include C₁₋₆ alkoxy groups (preferably C₁₋₄ alkoxy groups) such as a methoxy group, an ethoxy group, a propoxy group, an isopropyloxy group, a butoxy group, and an isobutyloxy group. Examples of the alkenyloxy group include C₂₋₆ alkenyloxy groups (preferably C₂₋₄ alkenyloxy groups) such as an allyloxy group. Examples of the aryloxy group include C₆₋₁₄ aryloxy groups optionally having a substituent such as a C₁₋₄ alkyl group, a C₂₋₄ alkenyl group, a halogen atom, or a C₁₋₄ alkoxy group in an aromatic ring, such as a phenoxy group, a tolyloxy group, a naphthyloxy group. Examples of the aralkyloxy group include C₇₋₁₈ aralkyloxy groups such as a benzyloxy group and a phenethyloxy group. Examples of the acyloxy group include C₁₋₁₂ acyloxy groups such as an acetyloxy group, a propionyloxy group, a (meth)acryloyloxy group, and a benzoyloxy group.

Examples of the alkylthio group include C₁₋₆ alkylthio groups (preferably C₁₋₄ alkylthio groups) such as a methylthio group and an ethylthio group. Examples of the alkenylthio group include C₂₋₆ alkenylthio groups (preferably C₂₋₄ alkenylthio groups) such as an allylthio group. Examples of the arylthio group include C₆₋₁₄ arylthio groups optionally having a substituent such as a C₁₋₄ alkyl group, a C₂₋₄ alkenyl group, a halogen atom, or a C₁₋₄ alkoxy group in an aromatic ring, such as a phenylthio group, a tolylthio group, a naphthylthio group. Examples of the aralkylthio group include C₇₋₁₈ aralkylthio groups such as a benzylthio group and a phenethylthio group. Examples of the alkoxycarbonyl group include C₁₋₆ alkoxy-carbonyl groups such as a methoxycarbonyl group, an ethoxycarbonyl group, a propoxycarbonyl group, and a butoxycarbonyl group. Examples of the aryloxycarbonyl group include C₆₋₁₄ aryloxy-carbonyl groups such as a phenoxycarbonyl group, a tolyloxycarbonyl group, and a naphthyloxycarbonyl group. Examples of the aralkyloxycarbonyl group include C₇₋₁₈ aralkyloxy-carbonyl groups such as a benzyloxycarbonyl group. Examples of the mono- or dialkylamino group include mono- or di-C₁₋₆ alkylamino groups such as a methylamino group, an ethylamino group, a dimethylamino group, and a diethylamino group. Examples of the acylamino group include C₁₋₁₁ acylamino groups such as an acetylamino group, a propionylamino group, and a benzoylamino group. Examples of the epoxy-containing group include a glycidyl group, a glycidyloxy group, and 3,4-epoxycyclohexyl group. Examples of the oxetanyl-containing group include an ethyloxetanyloxy group. Examples of the acyl group include an acetyl group, a propionyl group, and a benzoyl group. Examples of the halogen atom include a chlorine atom, a bromine atom, and an iodine atom.

The above monovalent heterocyclic groups may each have a substituent. Examples of the substituent include the same as the substituent optionally attached to the above monovalent hydrocarbon group.

Specific examples of the monovalent hydrocarbon group and the monovalent heterocyclic group include a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a phenyl group, a naphthyl group, an anthryl group, a benzyl group, a phenethyl group, a pyridyl group, a furyl group, a thienyl group, a vinyl group, an allyl group, a styryl group (e.g., p-styryl group), and substituted hydrocarbon groups (e.g., a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-glycidylpropyl group, a 3-methacryloxypropyl group, a 3-acryloxypropyl group, an N-2-(aminoethyl)-3-aminopropyl group, a 3-aminopropyl group, an N-phenyl-3-aminopropyl group, a 3-mercaptopropyl group, and a 3-isocyanatepropyl group).

In addition, the component (E) may have, as a group bonded to the silicon atom, a hydroxy group and/or an alkoxy group.

The form of component (E) may be a liquid or solid at 25° C. Preferred is a liquid.

The component (E) is preferably a polyorganosiloxysilalkylene represented by the following average unit formula: (R⁴ ₂SiO_(2/2))_(d1)(R⁴ ₃SiO_(1/2))_(d2)(R⁴SiO_(3/2))_(d3)(SiO_(4/2))_(d4)(R^(A))_(d5)(X⁷O_(1/2))_(d6).

Each R⁴ in the average unit formula is the same or different and is a hydrogen atom, a monovalent hydrocarbon group, or a monovalent heterocyclic group. Specific examples include the above-mentioned monovalent hydrocarbon groups and monovalent heterocyclic groups. Provided that a portion of R⁴ is a group containing an aliphatic carbon-carbon unsaturated bond (preferably an alkenyl group having 2 to 8 carbon atoms, in particular, a vinyl group) and a ratio of the group is controlled to be a range of one or more in a molecule. For example, the percentage of the groups containing an aliphatic carbon-carbon unsaturated bond based on the total amount (100 mol %) of R⁴ is preferably 0.1 to 40 mol %. When the percentage of the groups containing an aliphatic carbon-carbon unsaturated bond is adjusted to within the above range, the curable resin composition tends to have increased curing performance. In addition, preferable examples of R⁴ other than the groups containing an aliphatic carbon-carbon unsaturated bond include alkyl groups having 1 to 10 carbon atoms (in particular, a methyl group) and aryl groups having 4 to 14 carbon atoms (in particular, a phenyl group).

In the above average unit formula, R^(A) is a divalent hydrocarbon group as described above. Particularly preferred is an ethylene group.

In the above average unit formula, X⁷ is a hydrogen atom or an alkyl group. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a hexyl group. Particularly preferred is a methyl group.

In the above average unit formula, d1 is a positive number, d2 is a positive number, d3 is 0 or a positive number, d4 is 0 or a positive number, d5 is a positive number, and d6 is 0 or a positive number. Among them, d1 is preferably 1 to 200, d2 is preferably 1 to 200, d3 is preferably 1 to 10, d4 is preferably 0 to 5, and d5 is preferably 1 to 100. When (d3+d4) is a positive number, in particular, the component (E) has a branched-chain chain (a branched-chain main chain), so that the resulting cured product tends to have increased mechanical strength.

Specific examples of the component (E) include a polyorganosiloxysilalkylene having a structure represented by the following formula (IV-1):

[Chem. 5]

Each R⁴¹ in the above formula (IV-1) is the same or different and is a hydrogen atom, a monovalent hydrocarbon group, or a monovalent heterocyclic group. Specific examples of R⁴¹ include the above-mentioned monovalent hydrocarbon groups and monovalent heterocyclic groups. Provided that at least one of R⁴¹ is a group containing an aliphatic carbon-carbon unsaturated bond (preferably an alkenyl group having 2 to 8 carbon atoms, in particular, a vinyl group). In addition, preferable examples of R⁴¹ other than the groups containing an aliphatic carbon-carbon unsaturated bond include alkyl groups having 1 to 10 carbon atoms (in particular, a methyl group) and aryl groups having 6 to 14 carbon atoms (in particular, a phenyl group).

R^(A) in the above formula (IV-1) represents a divalent hydrocarbon group, as described above. In the group, a C₂₋₄ alkylene group (in particular, an ethylene group) is preferable. Note that when there are a plurality of R^(A), they may be the same or different.

In the above formula (IV-1), r1 represents an integer of 1 or more (e.g., 1 to 100). Note that when the r1 is an integer of 2 or more, each structure in parentheses to which r1 is attached may be the same or different.

In the above formula (IV-1), r2 represents an integer of 0 or 1 or more (e.g., 0 to 400). Note that when the r2 is an integer of 2 or more, each structure in parentheses to which r2 is attached may be the same or different.

In the above formula (IV-1), r3 represents an integer of 0 or 1 or more (e.g., 0 to 50). Note that when the r3 is an integer of 2 or more, each structure in parentheses to which r3 is attached may be the same or different.

In the above formula (IV-1), r4 represents an integer of 0 or 1 or more (e.g., 0 to 50). Note that when the r4 is an integer of 2 or more, each structure in parentheses to which r4 is attached may be the same or different.

In the above formula (IV-1), r5 represents an integer of 0 or 1 or more (e.g., 0 to 50). Note that when the r5 is an integer of 2 or more, each structure in parentheses to which r5 is attached may be the same or different.

How to add each structure unit in the above formula (IV-1) may include a random-type addition or a block-type addition. Also, the arrangement order of each structure unit is not particularly limited.

Preferably, the component (E) is a branched-chain polyorganosiloxysilalkylene represented by the above formula (IV-1) wherein r1 represents an integer of 1 or more (e.g., 1 to 100), r2 represents an integer of 1 or more (e.g., 1 to 400), r3 represents an integer of 1 or more (e.g., 1 to 50), r4 is 0, and r5 represents an integer of 1 or more (e.g., 1 to 50).

In addition, as another preferable aspect, the component (E) is a straight-chain polyorganosiloxysilalkylene where r1 represents an integer of 1 or more (e.g., 1 to 100), r2 represents an integer of 1 or more (e.g., 1 to 400), r3 and r4 are 0, and r5 represents an integer of 1 or more (e.g., 1 to 50).

Examples of the terminal structure of the polyorganosiloxysilalkylene having a structure represented by formula (IV-1) include a silanol group, an alkoxysilyl group, and a trialkylsilyl group (e.g., a structure in parentheses to which r5 is attached, such as a trimethylsilyl group). Various groups such as an alkenyl group and a hydrosilyl group may be introduced to the ends of the above polyorganosiloxysilalkylene.

The weight-average molecular weight (Mw) of the component (E) is not particularly limited, and preferably not less than 500 and not more than 50000, more preferably not less than 700 and not more than 20000, and still more preferably not less than 1000 and not more than 10000. When the weight-average molecular weight is 500 or more, the resulting cured product tends to have further increased toughness. Also, when the weight-average molecular weight is 50000 or less, the compatibility with the other components tends to increase. Note that the weight-average molecular weight is calculated by using molecular weights determined by gel permeation chromatography (GPC) in terms of standard polystyrene.

The molecular weight distribution (Mw/Mn) of the component (E) is not particularly limited, and preferably not less than 1 and not more than 4 and more preferably 1 to 3.5. When the molecular weight distribution is 4 or less, the compatibility of the resulting cured product tends to increase more. Note that the molecular weight distribution may be calculated by using a weight-average molecular weight (Mw) and a number average molecular weight (Mn) as calculated by using molecular weights determined by gel permeation chromatography (GPC) in terms of standard polystyrene.

The viscosity at 25° C. of the component (E) is not particularly limited, and preferably 100 mPa·s or higher and more preferably 500 mPa·s or higher. When the viscosity is 100 mPa·s or higher, the curable resin composition tends to be prepared and handled easily. Meanwhile, the upper limit of the viscosity is not particularly limited, and preferably 50000 mPa·s and more preferably 10000 mPa·s. When the viscosity is 50000 mPa·s or less, the compatibility tends to increase. Note that the viscosity at 25° C. may be measured by using substantially the same conditions as for the component (A).

The component (E) may be produced by a known and conventional process. Examples of the production process include the process described in JP2012-140617A, including making a hydrosilylation reaction of a polyorganosiloxane containing a group containing an aliphatic carbon-carbon unsaturated bond with a polyorganosiloxane containing a SiH group. The polyorganosiloxane containing a group containing an aliphatic carbon-carbon unsaturated bond and a polyorganosiloxane containing a SiH group as ingredients can be produced by known and conventional polyorganosiloxane production processes. They can be produced, without any particular limitation, by a process comprising: subjecting one or two or more different hydrolysable silane compounds to hydrolysis and condensation in the same manner as the production process of the above-described component (A). Alternatively, they may be commercially available products.

In addition, products containing the component (E) such as trade name “ETERLED GS5145”, “ETERLED GS5135”, and “ETERLED GS5120” (all manufactured by Eternal Materials Co., Ltd.) are available.

Note that in the present curable resin composition, the components (E) may be used singly or in combinations of two or more.

When two or more components (E) are used in combination, the d1 to d6, r1 to r5, etc., may each be an average as calculated in accordance with the blending ratio between the respective components (E).

Note that the component (E) has only to have a group containing one or more aliphatic carbon-carbon unsaturated bonds in a molecule and optionally further includes a hydrosilyl group.

When the curable resin composition of the present invention contains the component (E), the content (amount blended) thereof is not particularly limited and preferably 1 to 50 wt %, more preferably 1 to 40 wt %, and still more preferably 5 to 30 wt %, based on the total amount (100 wt %) of the curable resin composition. When the content is 1 wt % or more, the resulting cured product tends to have further increased toughness and transparency.

The content (amount blended) of the component (E) to the component (A) in the curable resin composition of the present invention is not particularly limited and, based on 100 parts by weight of the component (A), preferably 1 to 200 parts by weight, more preferably 5 to 100 parts by weight, and still more preferably 10 to 50 parts by weight. When the content is 1 part by weight or more, the resulting cured product tends to have further increased toughness and transparency.

[Component (F)]

The curable resin composition of the present invention may comprise a silsesquioxane having one or more alkenyl groups and one or more aryl groups in a molecule (sometimes referred to as “component (F)”). When the curable resin composition of the present invention contains the component (G), flexibility and heat shock resistance tend to increase. As the component (F), a silsesquioxane having one or more (preferably 2 or more) alkenyl groups and one or more (preferably 2 to 50) aryl groups in a molecule, may be used without any particular limitation.

Examples of the alkenyl group and the aryl group, which is contained in the molecule of component (F), include the same examples of the alkenyl group and the aryl group, which are contained in the molecule of component (A), as described above. The alkenyl group and the aryl group contained in the component (F) are not particularly limited, and a group bonded to a silicon atom is preferred.

Examples of the group bonded to a silicon atom other than the alkenyl group and the aryl group, which are contained in the molecule of component (F) are not particularly limited, and include a hydrogen atom and an organic group. Examples of the organic group include the substituted or unsubstituted monovalent hydrocarbon groups described above. Note that “a group bonded to a silicon atom” in the present specification usually means a group containing no silicon atom. Among them, preferred is an alkyl group (in particular, a methyl group).

Further, the component (F) may have a hydroxy group or an alkoxy group, as the group bonded to a silicon atom.

The percentage of the alkenyl group in the entire component (G) (100 wt %) is not particularly limited as long as the percentage is controlled to be a range of one or more in a molecule, and for example, 1.0 to 20.0 wt %, and preferably 1.5 to 15.0 wt %. The percentage of the aryl group is not particularly limited as long as the percentage is controlled to be a range of one or more in a molecule, and for example, 1.0 to 50.0 wt %, and preferably 5.0 to 25.0 wt %. Controlling an alkenyl group within the above-mentioned range tends to give a cured product having various excellent properties such as heat resistance and excellent crack resistance. The percentage of the alkyl group is not particularly limited, and is for example, 10.0 to 50.0 wt %, and preferably 20.0 to 40.0 wt %. Note that the percentage (mol %) of the alkenyl group, the aryl group or the alkyl group can be calculated, for example, based on the measurement of an NMR spectroscopy (for example, ¹H-NMR spectroscopy).

Silsesquioxane is a polysiloxane having, as a basic constitutional unit, a T unit (a unit constituting of a trivalent group in which a silicon atom is bonded to 3 oxygen atoms), and its empirical formula (basic structural formula) is represented by RSiO_(1.5). Examples of the Si—O—Si structure contained in the silsesquioxane include a random structure, a cage structure and a ladder structure.

In the component (F), the number of the alkenyl group in a molecule is not particularly limited, and may be one or more, preferably 2 to 50, and more preferably 2 to 30. Having the alkenyl groups in the above range, a cured product excellent in various physical properties such as heat resistance, and the crack resistance tends to be easily obtained. Note that the number of the alkenyl group can be calculated, for example, by ¹H-NMR spectroscopy.

The weight-average molecular weight (Mw) of the component (F) is not particularly limited, and is preferably 100 to 800000, more preferably 200 to 100000, still more preferably 300 to 10000, particularly preferably 500 to 8000, and most preferably 1700 to 7000. When the Mw is less than 100, the cured product may have reduced heat resistance. Meanwhile, when the Mw is more than 800000, the compatibility with other components may be reduced. Note that the Mw can be calculated from the molecular weights determined by gel permeation chromatography in terms of standard polystyrene.

The number-average molecular weight (Mn) of the component (F) is not particularly limited, and is preferably 80 to 800000, more preferably 150 to 100000, still more preferably 250 to 10000, particularly preferably 400 to 8000, and most preferably 1500 to 7000. When the Mn is less than 80, the cured product may have reduced heat resistance. Meanwhile, when the Mn is more than 800000, the compatibility with other components may be reduced. Note that the Mn can be calculated from the molecular weights determined by gel permeation chromatography in terms of standard polystyrene.

The molecular weight distribution (Mw/Mn) in terms of standard polystyrene determined by gel permeation chromatography of the component (F) is not particularly limited, and is preferably 1.00 to 1.40, more preferably 1.35 or less (for example, 1.05 to 1.35), still more preferably 1.30 or less (for example, 1.10 to 1.30). When the molecular weight distribution is more than 1.40, for example, a low molecular weight siloxane increases, so that the cured product tends to have reduced attachment. Meanwhile, when the molecular weight distribution is 1.05 or more, the curable resin composition easily becomes liquid (in a liquid form) at room temperature, so that increased handling may be achieved.

Note that the number average molecular weight and the molecular weight distribution of the component (F) can be measured by the following devices under the following conditions:

Alliance HPLC System 2695 (manufactured by Waters); Refractive Index Detector 2414 (manufactured by Waters);

Column: Tskgel GMH_(HR)-M×2 (manufactured by Tosoh Corporation);

Guard column: Tskgel guard column HHRL (manufactured by Tosoh Corporation);

Column oven: COLUMN HEATER U-620 (manufactured by Sugai);

Solvent: THF;

Measurement Temperature: 40° C.;

Molecular weight: in terms of standard polystyrene.

Preferably, the component (F) is a liquid at normal temperature (about 25° C.). More specifically, the viscosity at 23° C. is preferably 100 to 100000 mPa·s, more preferably 500 to 10000 mPa·s, and still more preferably 1000 to 8000 mPa·s. When the viscosity is less than 100 mPa·s, the heat resistance of the cured product may be reduced. Meanwhile, when the viscosity is more than 100000 mPa·s, preparation and handling of the curable resin composition may be difficult. Note that the viscosity at 23° C. can be measured under conditions at a temperature of 23° C. and a rotation number of 8 rpm by using a rheometer (trade name “Physica UDS-200” manufactured by Anton Paar, Inc.) and a cone plate (with a cone diameter of 16 mm and a taper angle of 0°).

The component (F) in the curable resin composition of the present invention may be used singly or may be used in combination of two or more.

From the viewpoints of the strength (resin strength), the flexibility and the heat shock resistance, the curable resin composition of the present invention preferably contains the component (F).

When the curable resin composition of the present invention contains the component (F), the content (amount blended) of the component (F) in the curable resin composition is not particularly limited, and is preferably 0.05 to 50 parts by weight, more preferably 0.1 to 45 parts by weight, and still more preferably 0.2 to 40 parts by weight, based on a total amount of the component (A) and the component (B) of 100 parts by weight. Further, the content (amount blended) of the component (F) is not particularly limited, and is preferably 0.01 to 20 wt %, more preferably 0.05 to 15 wt %, and still more preferably 0.1 to 10 wt %, based on the curable resin composition (100 wt %). When the content of the component (F) is controlled to within the above ranges, the resulting cured product tends to have markedly increased flexibility and heat shock resistance.

[Silane Coupling Agent (G)]

The curable resin composition of the present invention may further comprise a silane coupling agent (G). When the silane coupling agent (G) is contained, the resulting cured product tends to, in particular, have more improved adhesion to an adherend.

As the silane coupling agent (G), known and conventional silane coupling agents can be used. Examples include: epoxy-containing silane coupling agents such as 3-glycidoxypropyl trimethoxysilane, 2-(3,4-epoxycyclohexyl) ethyl trimethoxysilane, 3-glycidoxypropylmethyl diethoxysilane, 3-glycidoxypropyl triethoxysilane; amino-containing silane coupling agents such as N-2-(aminoethyl)-3-aminopropylmethyl dimethoxysilane, N-2-(aminoethyl)-3-aminopropyl trimethoxysilane, N-2-(aminoethyl)-3-aminopropyl triethoxysilane, 3-aminopropyl trimethoxysilane, 3-aminopropyl triethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyl trimethoxysilane, N-(vinylbenzyl)-2-aminoethyl-3-aminopropyl trimethoxysilane hydrochloride, N-(β-aminoethyl)-γ-aminopropylmethyl dimethoxysilane; tetramethoxysilane, tetraethoxysilane, methyl triethoxysilane, dimethyl diethoxy silane, methyl triethoxysilane, vinyl triethoxysilane, vinyl trimethoxysilane, vinyl tris(methoxyethoxysilane), phenyltrimethoxysilane, diphenyl dimethoxysilane, vinyl triacetoxysilane, γ-(meth)acryloyloxypropyl triethoxysilane, γ-(meth)acryloylxypropyl trimethoxysilane, γ-(meth)acryloyloxypropylmethyl dimethoxysilane, γ-(meth)acryloyloxypropylmethyl diethoxysilane, mercaptopropylene trimethoxysilane, mercaptopropylene triethoxysilane, and alkoxy oligomers (e.g., trade names “X-41-1053”, “X-41-1059A”, “KR-516”, “X-41-1085”, “X-41-1818”, “X-41-1810”, “X-40-2651”, “X-40-2665A”, “KR-513”, “KC-89S”, “KR-500”, “X-40-9225”, “X-40-9246”, “X-40-9250”; each manufactured by Shin-Etsu Chemical Co., Ltd.). Among them, the epoxy-containing silane coupling agents (in particular, 3-glycidoxypropyl trimethoxysilane) are preferably used.

In the present curable resin composition, the silane coupling agents (G) may be used singly or in combinations of two or more. Alternatively, the silane coupling agents (G) may be commercially available products.

When the curable resin composition of the present invention contains the silane coupling agent (G), the content (amount blended) of the silane coupling agent (G) in the present curable resin composition is preferably 0.01 to 15 wt %, more preferably 0.1 to 10 wt %, and still more preferably 0.5 to 5 wt %, based on the total amount (100 wt %) of the curable resin composition. When the content of the silane coupling agent (G) is 0.01 wt % or more, the resulting cured product tends to have more improved adhesion to an adherend. Meanwhile, when the content of the silane coupling agent (G) is 15 wt % or less, the curing reaction fully proceeds, and the resulting cured product tends to have much better toughness, and heat resistance.

Further, the present curable resin composition may contain a component other than the above-described components (sometimes simply referred to as an “additional component”). Examples of the additional component include: siloxane compounds other than the components (A), (B), (E), and (F) (e.g., cyclic siloxane compounds, low-molecular-weight, straight-chain or branched-chain siloxane compounds); hydrosilylation inhibitors; solvents; and various additives. Examples of the additives include: inorganic fillers such as precipitated silica, wet silica, fumed silica, calcined silica, titanium oxide, alumina, glass, quartz, aluminosilicate, iron oxide, calcium carbonate, carbon black, silicon carbide, silicon nitride, and boron nitride; inorganic fillers as obtained by processing each filler with an organic silicon compound such as an organohalosilane, organoalkoxysilane, or organosilazane; other organic resin (e.g., a silicone resin, an epoxy resin, a fluorine resin) fine powders; fillers such as conductive metal powders (e.g., silver, copper); solvents; stabilizers (e.g., antioxidants, UV absorbers, photostabilizers, thermal stabilizers); fire retardants (e.g., phosphorus-based fire retardants, halogen-based fire retardants, inorganic fire retardants); fire retardant aids; reinforcement materials (e.g., other fillers); nucleating agents; coupling agents; lubricants; waxes; plasticizers; mold release agents; impact resistance enhancers; color enhancers; fluidity enhancers; coloring agents (e.g., dyes, pigments); dispersers; antifoam agents; defoaming agents; antimicrobials; preservatives; viscosity modifiers; thickeners; and phosphors. The above additional components may be used singly or in combinations of two or more. Note that the content (amount blended) of the additional component may be suitably selected as long as the effects of the present invention are not impaired.

In the present curable resin composition, the composition (blending composition) is provided such that the amount of the hydrosilyl group (SiH group) in the component (B) per mol of the alkenyl group (including an aliphatic carbon-carbon double bond-containing group) present in the curable resin composition is preferably not less than 0.1 mol and not more than 100 mol, more preferably 0.3 to 50 mol, and still more preferably 0.5 to 30 mol. When the percentage of the alkenyl group and the hydrosilyl group is controlled to within the above ranges, the resulting cured product tends to have further increased heat resistance, transparency, heat shock resistance, and reflow resistance.

The present curable resin composition may be prepared by stirring and mixing each of the above components at room temperature. Note that the present curable resin composition may be used as a one-liquid composition, in which a pre-mixture of each of the components may be used as it is, or, for example, as a composition made of multiple liquids (e.g., two liquids) to be used after mixing two or more components, which have been separately stored, at a prescribed ratio before use. During the preparation, the liquids may be heated to about a temperature at which they are not cured (e.g., 30 to 100° C.)

The present curable resin composition may be in either a solid or liquid state and is usually a liquid at room temperature (about 25° C.)

The curable resin composition of the present invention has a viscosity at 23° C. of preferably 300 to 20000 mPa·s, more preferably 500 to 10000 mPa·s, and still more preferably 1000 to 8000 mPa·s. When the viscosity is 300 mPa·s or more, the resulting cured product tends to have increased heat resistance. Also, when the viscosity is 20000 mPa·s or less, the curable resin composition tends to be easily prepared, so that the yield and handling easiness increase. In addition, because foams are unlikely to remain in the resulting cured product, the yield and qualities of the cured product (in particular, an encapsulant) tend to further increase. Note that the viscosity of the curable resin composition can be measured by the same method as for the viscosity of the above-described component (A).

<Cured Product>

The curable resin composition of the present invention may be cured (in particular, cured by hydrosilylation) to yield a cured product (sometimes simply referred to as the “present cured product”). Curing (in particular, hydrosilylation-mediated curing) conditions may be suitably selected from conventional and known conditions. For instance, in view of the reaction rate, the temperature (curing temperature) is preferably 25 to 180° C. and more preferably 60 to 150° C., and the time (curing time) is preferably 5 to 720 min. Note that the curing may be conducted in one step or multistep. The present cured product has not only high heat resistance and transparency, which are specific to polysiloxane-based materials, but also flexibility and heat shock resistance properties against corrosive gas and is also less tacky. In particular, in the high-temperature heat resistance test and the high-brightness light resistance test, the cured product has suppressed transmittance reduction and suppressed hardness rise over time, and maintained flexibility.

The present cured product has a solid refractive index at light beam of 589 nm and at 25° C. of preferably 1.46 to 1.54, more preferably 1.465 to 1.535, and still more preferably 1.47 to 1.53. When having a solid refractive index of 1.46 or more, the present cured product tends to be less tacky. Also, when having a solid refractive index of 1.54 or less, the cured product tends to have increased heat resistance and light resistance. Note that the above solid refractive index can be measured by using a Prism Coupler Model 2010/M (manufactured by Metricon Corporation).

<Encapsulating Agent>

The curable resin compositions of the present invention may each be suitably used as a composition (encapsulating agent) for encapsulating a semiconductor element in a semiconductor device (sometimes simply referred to as the “present encapsulating agent”). Specifically, the present encapsulating agents may be particularly preferably used as applications for encapsulating optical semiconductor elements in an optical semiconductor device (i.e., as encapsulating agents for optical semiconductors). Each encapsulant (cured product) as obtained by curing the present encapsulating agent has not only high heat resistance and transparency, which are specific to polysiloxane-based materials, but also flexibility and heat shock resistance properties, and is also less tacky. In particular, in the high-temperature heat resistance test and the high-brightness light resistance test, the encapsulant has suppressed transmittance reduction and suppressed hardness rise over time, and maintained flexibility. Consequently, the encapsulating agent of the present invention can be favorably used particularly as an encapsulating agent for high-brightness and short-wavelength optical semiconductor elements having a large size.

<Lens-Forming Resin Composition>

In addition, the curable resin compositions of the present invention may be suitably used as lens-forming resin compositions (sometimes referred to as the “present lens-forming resin composition”). Each lens as obtained by curing the present lens-forming resin composition has not only high heat resistance and transparency, which are specific to polysiloxane-based materials, but also flexibility and heat shock resistance properties and is also less tacky. In particular, in the high-temperature heat resistance test and the high-brightness light resistance test, the lens has suppressed transmittance reduction and suppressed hardness rise over time, and maintained flexibility. Because of this, each lens as obtained by curing the present lens-forming resin composition can be preferably used as a lens, etc., for high-brightness and short-wavelength optical semiconductor elements.

<Semiconductor Device>

The present encapsulating agent may be used to encapsulate a semiconductor element so as to obtain a semiconductor device (sometimes simply referred to as the “present semiconductor device”). That is, the present semiconductor device is a semiconductor device having at least a semiconductor element and an encapsulant that encapsulates the semiconductor element, wherein the encapsulant is a cured product of the present encapsulating agent. In addition, the present lens-forming resin composition may be used to produce a semiconductor device (also sometimes referred to as the “present semiconductor device”). Furthermore, another aspect of the present semiconductor device provides a semiconductor device having at least a semiconductor element and a lens, wherein the lens is a cured product of the present lens-forming resin composition.

The present semiconductor device may be a semiconductor device including a semiconductor element, an encapsulant that encapsulates the semiconductor element, and a lens, wherein the encapsulant is a cured product of one of the curable resin compositions of the present invention (the present encapsulating agent) and the lens is a cured product of one of the curable resin compositions of the present invention (the present lens-forming resin composition).

The present semiconductor devices can be manufactured by using known and conventional procedures. For instance, the present encapsulating agent and/or lens-forming resin composition may be injected into a predetermined mold and then heated and cured under predetermined conditions to produce the present semiconductor devices. The curing temperature and curing time may be set to within substantially the same ranges as when the cured product is prepared.

When the above semiconductor device is an optical semiconductor device, namely when the present encapsulating agent and/or lens-forming resin composition are used as an encapsulating agent for an optical semiconductor element (encapsulating agent for an optical semiconductor) and/or a lens-forming resin composition (lens-forming resin composition for an optical semiconductor) in an optical semiconductor device, they can effectively exert, in particular, the above-mentioned advantageous effects. The present encapsulating agent and/or lens-forming resin composition may be used as an encapsulating agent for an optical semiconductor to obtain an optical semiconductor device (sometimes simply referred to as the “present optical semiconductor device”).

FIG. 1 shows an optical semiconductor device according to an embodiment of the present invention. In FIG. 1, “100” denotes a reflector (light-reflecting resin composition); “101” denotes metal wiring (electrode); “102” denotes an optical semiconductor element; “103” denotes a bonding wire; and “104” denotes a cured product (encapsulant).

Specifically, the curable resin compositions of the present invention may be suitably used for applications such as: encapsulating agents that encapsulate each optical semiconductor element and/or lens-forming resin compositions which are used in high-brightness, short-wavelength and large optical semiconductor devices; and encapsulating agents for forming encapsulants that encapsulate each semiconductor element in high heat-resistant and voltage-resistant semiconductor devices (e.g., power semiconductors), all of which have hardly been realized by using conventional resin materials.

The curable resin compositions of the present invention are not limited to the above-mentioned encapsulating agent applications (in particular, encapsulating agent applications for optical semiconductor elements) and lens formation applications (in particular, lens formation applications for optical semiconductor devices). Examples of preferable usage include optics-related and/or semiconductor-related applications such as functional coating agents, transparent devices, adhesives (e.g., heat-resistant, transparent adhesives), electrical insulators (e.g., insulating films), laminated plates, coatings, inks, paints, sealants, resists, composite materials, transparent substrates, transparent sheets, transparent films, optical elements, optical members, photo fabrication, electrical papers, touch panels, solar cell boards, optical waveguides, light-guiding plates, and holographic memories.

EXAMPLES

Hereinafter, the present invention will be described in detail based on Examples. The present invention, however, is not limited thereto.

The resulting products and manufactured articles were analyzed by ¹H-NMR analysis using JEOL ECA500 (at 500 MHz).

The number average molecular weight and weight-average molecular weight of each of the resulting products and manufactured articles were measured in terms of standard polystyrene by using an Alliance HPLC System 2695 (manufactured by Waters), a Refractive Index Detector 2414 (manufactured by Waters), a column: Tskgel GMHHR-M×2 (manufactured by Tosoh Corporation), a guard column: Tskgel guard column HHRL (manufactured by Tosoh Corporation), a column oven: COLUMN HEATER U-620 (manufactured by Sugai), and a solvent: THF under measurement conditions at 40° C.

The viscosity of each of the resulting products and manufactured articles was measured under conditions at a temperature of 25° C. and a rotation number of 20 rpm by using a rheometer (trade name “Physica MCR-302”) manufactured by Anton Paar, Inc., and a parallel plate (with a cone diameter of 25 mm and a cone angle of 0 degrees).

The solid refractive index of each of the resulting products and manufactured articles was measured by using a Prism Coupler Model 2010/M (manufactured by Metricon Corporation) and the refractive index at 589.0 nm was calculated from the readings at 407.3 nm, 632.8 nm, 827.8 nm, and 1310.2 nm under an environment at 25° C.

Production Example 1

To a 500-mL four-neck flask were added 60.02 g (288.10 mmol) of tetraethoxysilane, 14.79 g (74.74 mmol) of trimethoxyphenylsilane, 11.96 g (73.65 mmol) of hexamethyldisiloxane, 2.87 g (15.40 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, and 65.27 g of methyl isobutyl ketone. The mixture was cooled to 15° C., and 18.38 g of 5 N hydrochloric acid placed in a dropping funnel was then added dropwise. Further, 24.78 g of water was added dropwise. After that, the resulting mixture was heated to 80° C. and then stirred. Subsequently, 60.96 g (375.42 mmol) of hexamethyldisiloxane and 14.40 g (77.25 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane were further added and the mixture was then stirred.

Next, the resulting reaction solution was transferred to a separating funnel; only a lower layer containing a silicone resin was removed; and this liquid was transferred to the separating funnel again and was then washed with water.

After the water washing, a solvent portion was removed under reduced pressure by using a rotary evaporator to yield 38.95 g of silicone resin A-1.

The number average molecular weight (Mn): 2038, the weight-average molecular weight (Mw): 2427, the molecular weight distribution (Mw/Mn): 1.19.

¹H-NMR (JEOL ECA500 (500 MHz, CDCl₃)) δ: −0.3-0.3 ppm (br), 3.0-4.0 ppm (br), 5.7-6.2 ppm (br), 7.1-7.9 ppm (br).

The average unit formula: (SiO_(4/2))_(0.44)(PhSiO_(3/2))_(0.12)(Me₃SiO_(1/2))_(0.37)(ViMe₂SiO_(1/2))_(0.07) [Ph: a phenyl group, Me: a methyl group, Vi: a vinyl group; the same applies to the following].

The methyl group content: 87 mol %, the phenyl group content: 8 mol %, the vinyl group content: 5 mol %.

Production Example 2

To a 500-mL four-neck flask were added 45.57 g (218.75 mmol) of tetraethoxysilane, 26.03 g (131.25 mmol) of trimethoxyphenylsilane, 8.32 g (51.27 mmol) of hexamethyldisiloxane, 5.73 g (30.76 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, and 67.98 g of methyl isobutyl ketone. The mixture was cooled to 15° C., and 16.35 g of 5 N hydrochloric acid placed in a dropping funnel was then added dropwise. Further, 22.05 g of water was added dropwise. After that, the resulting mixture was heated to 80° C. and then stirred. Subsequently, 41.62 g (256.33 mmol) of hexamethyldisiloxane and 28.67 g (153.80 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane were further added and the mixture was then stirred.

Next, the reaction solution was transferred to a separating funnel; only a lower layer containing a silicone resin was removed; and this liquid was transferred to the separating funnel again and was then washed with water.

After the water washing, a solvent portion was removed under reduced pressure by using a rotary evaporator to yield 37.85 g of silicone resin A-2.

The number average molecular weight (Mn): 2670, the weight-average molecular weight (Mw): 3250, the molecular weight distribution (Mw/Mn): 1.22.

¹H-NMR (JEOL ECA500 (500 MHz, CDCl₃)) δ: −0.3-0.3 ppm (br), 3.0-4.0 ppm (br), 5.7-6.2 ppm (br), 7.1-7.9 ppm (br).

The average unit formula: (SiO_(4/2))_(0.35)(PhSiO_(3/2))_(0.21)(Me₃SiO_(1/2))_(0.30)(ViMe₂SiO_(1/2))_(0.14.)

The methyl group content: 77 mol %, the phenyl group content: 14 mol %, the vinyl group content: 9 mol %.

Production Example 3

To a 500-mL four-neck flask were added 22.53 g (108.2 mmol) of tetraethoxysilane, 161.85 g (1188.2 mmol) of methyltrimethoxysilane, 66.59 g (335.8 mmol) of phenyltrimethoxysilane, 271.91 g (2.9511 mmol) of toluene, and 181.22 g (3.9336 mmol) of ethanol. The mixture was cooled to 15° C., and 66.79 g of 5 N hydrochloric acid placed in a dropping funnel was then added dropwise. Further, 90.08 g of water was added dropwise. After that, the resulting mixture was heated to 72° C. and then stirred.

Subsequently, 174.03 g (1.0718 mmol) of hexamethyldisiloxane and 254.25 g (1.3640 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane were further added and the mixture was then stirred.

Next, the reaction solution was transferred to a separating funnel; only a lower layer containing a silicone resin was removed; and this liquid was transferred to the separating funnel again and was then washed with water.

After the water washing, a solvent portion was removed under reduced pressure by using a rotary evaporator to yield 153 g of silicone resin A-3.

The number average molecular weight (Mn): 2079, the weight-average molecular weight (Mw): 4086, the molecular weight distribution (Mw/Mn): 1.97.

¹H-NMR (JEOL ECA500 (500 MHz, CDCl₃)) δ: −0.15-0.15 ppm (br), 1.25-1.25 ppm (br), 3.58-3.86 ppm (br), 5.75-6.16 ppm (br), 7.38-7.73 ppm (br).

The average unit formula: (SiO_(4/2))_(0.06)(MeSiO_(3/2))_(0.61)(PhSiO_(3/2))_(0.17)(Me₃SiO_(1/2))_(0.09)(ViMe₂SiO_(1/2))_(0.07).

The methyl group content: 81 mol %, the phenyl group content: 14 mol %, the vinyl group content: 5 mol %.

Production Example 4

(Step 1)

To a 100-mL flask with a reflux tube were added, under a nitrogen atmosphere, 6.653 g (20 mmol; a hydrosilyl group: 40 mmol) of 3,3-diphenyl-1,1,5,5-tetramethyl trisiloxane, 7.520 g of toluene, and 0.0018 g [1.9×10⁻⁴ mmol (in terms of Pt)] of a xylene solution containing a platinum (2%)-divinyltetramethyldisiloxane complex. Next, the mixture was stirred and preserved at 60° C.

Then, 6.155 g (16 mmol; a vinylsilyl group: 32 mmol) of 1,5-divinyl-3,3-diphenyl-1,1,5,5-tetramethyltrisiloxane was added dropwise thereto by using a dropping funnel.

After completion of the dropwise addition, the mixture was preserved at 60° C. to produce a reaction solution containing a straight-chain polyorganosiloxysilalkylene having hydrosilyl groups at both ends. Thereafter, the reaction solution was cooled to room temperature.

(Step 2)

To a 100-mL flask with a reflux tube were added, under a nitrogen atmosphere, 2.000 g (4.8 mmol) of tris(vinyldimethylsiloxy)phenylsilane and 0.0744 g [8×10⁻⁵ mmol (in terms of Pt)] of a xylene solution containing a platinum (0.02%)-divinyltetramethyldisiloxane complex. Next, the mixture was preserved at 100° C.

All the amount of the reaction solution obtained in Step 1 was added dropwise thereto by using a dropping funnel. Then, the mixture was cooled to room temperature.

After the cooling, a solvent was removed from this reaction solution by using an evaporator to concentrate the solution until toluene as measured by gas chromatograph (trade name “GC-2010”; manufactured by Shimadzu Corporation) was undetected so as to produce 14.2 g of vinylsilyl-containing polyorganosiloxysilalkylene E-1.

The viscosity [at 25° C. when the shear rate was 20 (1/s)] was 3200 mPa·s, the number average molecular weight (Mn) was 3329, the weight-average molecular weight (Mw) was 7327, and the molecular weight distribution (Mw/Mn) was 2.20.

¹H-NMR (JEOL ECA500 (500 MHz, CDCl₃)) δ: −0.3-0.3 ppm (br), 0.4 ppm (br), 3.0-4.0 ppm (br), 5.7-6.2 ppm (br), 7.1-7.9 ppm (br).

Production Example 5

(Step 1)

First, 13.10 g (66.1 mmol) of phenyltrimethoxysilane, 4.500 g (33.0 mmol) of methyltrimethoxysilane, 12.31 g (66.1 mmol) of 1,1,3,3-tetramethyl-1,3-divinyldisiloxane, and 6.16 g of methyl isobutyl ketone (MIBK) were added under a nitrogen air stream to a 100-ml flask (reaction vessel) equipped with a thermometer, a mixer, a reflux condenser, and a nitrogen inlet. Next, the mixture was heated to 70° C. To this mixture were simultaneously added dropwise 5.74 g (319 mmol) of water and 0.32 g of 5 N hydrochloric acid (4.8 mmol of hydrogen chloride) and the mixture was subjected to a polycondensation reaction at 70° C.

The resulting mixture was then cooled and washed with water until a lower layer liquid became neutral. After an upper layer liquid was separated, a solvent was evaporated from the upper layer liquid under conditions at 1 mmHg and at 40° C. to give a colorless, transparent, solid product (20.52 g). This product (a product after the silylation reaction) had a number average molecular weight of 720 and a weight-average molecular weight of 840.

(Step 2)

To a 100-mL flask with a reflux tube were added 20.00 g of the product obtained in Step 1, 17.95 g (47 mmol) of 3,3-diphenyl-1,1,5,5-tetramethyl trisiloxane, 7.520 g of toluene, and 0.0018 g [1.9×10⁻⁴ mmol (in terms of Pt)] of a xylene solution containing a platinum (2%)-divinyltetramethyldisiloxane complex. Next, the mixture was stirred and preserved at 60° C.

After cooling, a solvent was removed from the reaction solution by using an evaporator to concentrate the solution until toluene as measured by gas chromatograph (trade name “GC-2010”; manufactured by Shimadzu Corporation) was undetected so as to produce 34.85 g of vinylsilyl-containing polyorganosiloxysilalkylene E-2.

The viscosity [at 25° C. when the shear rate was 20 (1/s)] was 1100 mPa·s, the number average molecular weight (Mn) was 1072, the weight-average molecular weight (Mw) was 2676, and the molecular weight distribution (Mw/Mn) was 2.50.

¹H-NMR (JEOL ECA500 (500 MHz, CDCl₃)) δ: −0.3-0.3 ppm (br), 0.4 ppm (br), 3.0-4.0 ppm (br), 5.7-6.2 ppm (br), 7.1-7.9 ppm (br).

Production Example 6

A 200-mL four-neck flask was charged with 42.61 g (238.98 mmol) of triethoxymethylsilane, 6.76 g (28.12 mmol) of phenyltriethoxysilane, and 17.69 g of methyl isobutyl ketone. The mixture was cooled to 10° C. To the mixture, 4.33 g of water and 0.48 g of 5 N hydrochloric acid (i.e., 2.4 mmol of hydrogen chloride) were added dropwise at the same time. After the dropping, the mixture was held at 10° C. Subsequently, 80.0 g of methyl isobutyl ketone was added thereto to dilute the reaction solution.

Subsequently, the temperature of the reaction vessel was raised to 70° C., and then 10.91 g of water was added into the vessel when the temperature reached 70° C., so that a polycondensation reaction was performed at the same temperature. Further, 2.08 g (10.93 mmol) of vinyltriethoxysilane was added thereto, so that a reaction (maturing) was performed at the same temperature.

Subsequently, 15.0 g (92.38 mmol) of hexamethyldisiloxane was added to the resulting reaction solution, so that a silylation reaction was performed at 70° C. The reaction solution was then cooled and washed with water until a lower layer liquid became neutral. An upper layer liquid was then separated. Subsequently, the solvent was evaporated from the upper layer liquid under conditions at 1 mmHg and at 60° C. to give 19.0 g of a silsesquioxane having a vinyl group and a TMS group at the ends as a colorless and transparent liquid product.

-   -   Weight-average molecular weight (Mw): 2700     -   Content of phenyl group: 4 mol %     -   Content of vinyl group: 2 mol %     -   ¹H-NMR (JEOL ECA500 (500 MHz, CDCl₃)) δ: −0.3-0.3 ppm (br),         5.7-6.2 ppm (br), 7.1-7.7 ppm (br).

As the component (A), the following products were each used:

-   -   resin A-1: the product obtained in Production Example 1;     -   resin A-2: the product obtained in Production Example 2;     -   resin A-3: the product obtained in Production Example 3;

As the component (B), the following manufactured articles were each used:

Si—H monomer B-1: 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane (manufactured by NANJING SiSiB Silicones, Inc.) having

-   -   the average composition formula:         Ph_(2/3)Me_(4/3)H_(2/3)SiO_(2/3),     -   the average unit formula: (Ph₂SiO_(2/2))₁(HMe₂SiO_(1/2))₂, and     -   a methyl group content of 50 mol %, a phenyl group content of 25         mol %, and a hydrosilyl group content of 25 mol %; and     -   Si—H monomer B-2: 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane         (manufactured by Gelest Inc.) having     -   the average composition formula:         Ph_(1/3)Me_(5/3)H_(2/3)SiO_(2/3),     -   the average unit formula: (MePhSiO_(2/2))₁(HMe₂SiO_(1/2))₂, and     -   a methyl group content of 62.5 mol %, a phenyl group content of         12.5 mol %, and a hydrosilyl group content of 25 mol %.

Si—H monomer B-3: trade name “DMS-H03” (manufactured by Gelest Inc.) having

-   -   the average composition formula: Me₂H_(1/3)SiO_(5/6),     -   the average unit formula: (Me₂SiO_(2/2))₄(HMe₂SiO_(1/2))₂,     -   viscosity: 2 mPa·s (25° C.),     -   molecular weight: 436, and     -   a methyl group content of 85.7 mol %, a phenyl group content of         0 mol %, and a hydrosilyl group content of 14.3 mol %.

As the component (C), the following manufactured articles were each used:

-   -   zirconium compound C-1: trade name “ZAA”         [tetra-n-propoxyzirconium], manufactured by Nippon Soda Co.,         Ltd.     -   zirconium compound C-2: trade name “octope Zr” [zirconium         2-ethylhexanoate, containing 27% of ink solvent as a solvent],         manufactured by Hope Chemical Co., Ltd.

As the component (D), the following manufactured article was used:

-   -   an addition reaction catalyst: trade name “Pt-VTS”, a xylene         solution containing a platinum-divinyltetramethyldisiloxane         complex, and having a content of platinum of 2.0 wt %;         manufactured by N.E. CHEMCAT CORPORATION.

As the component (E), the following products were each used:

-   -   vinylsilalkylene E-1: the product obtained in Production Example         4; and     -   vinylsilalkylene E-2: the product obtained in Production Example         5.

As the component (F), the following product was used:

-   -   silsesquioxane: the product obtained in Production Example 6.

EXAMPLES AND COMPARATIVE EXAMPLES

Examples 1 to 7 and Comparative Examples 1 to 4 were put into practice in accordance with the following protocols.

The components (A), (B), (C), (E), and (F) were mixed at a given weight ratio according to Table 1 (Examples 1 to 7 and Comparative Examples 1 to 4), and each mixture was stirred at 70° C. for 2 h. Next, the mixture was cooled to room temperature, and the component (D) was added at a prescribed weight ratio and then stirred for 10 min to give a curable resin composition as a uniform liquid.

Table 1 shows a1/a2 of the component (A) included in each curable resin composition obtained in each of Examples and Comparative Examples. If two or more resins were used as the component (A), a1/a2 was a weight average based on the blending ratio between the resins.

In addition, Table 1 shows the ratio of the hydrosilyl group (SiH group) in the component (B) to the vinyl group (SiVi group) in the curable resin composition (SiH/SiVi ratio).

Each resin composition was subjected to the following evaluation tests.

Note that unless otherwise indicated, the amount of each component blended of each curable resin composition in Table 1 is expressed as parts by weight; and the amounts of the component (C) and component (D) are expressed by parts per million (ppm) of zirconium and platinum, respectively.

<Evaluation>

[Solid Refractive Index]

Each curable resin composition as obtained above was injected into a mold made of PTFE with a thickness of 0.5 mm and was heated at 80° C. for 1 h and further heated at 150° C. for 4 h to produce, from each curable resin composition, a cured product, which was then subjected to a solid refractive index measurement.

The refractive index at 589.0 nm of each cured product obtained was calculated from the readings at 407.3 nm, 632.8 nm, 827.8 nm, and 1310.2 nm under an atmosphere at 25° C. as obtained by using a Prism Coupler Model 2010/M (manufactured by Metricon Corporation). Table 1 shows the results.

[Aging Test]

(To Produce Cured Product)

Each curable resin composition as obtained above was injected into a rectangular mold with a thickness of 3 mm, a width of 10 mm, and a length of 50 mm, and was heated at 80° C. for 1 h and further heated at 150° C. for 6 h to produce, from each curable resin composition, a cured product (with a thickness of 3 mm).

The light transmittance at 450 nm of each cured product as produced above was measured by using a spectrophotometer (UV-2450, manufactured by Shimadzu Corporation), and the D hardness of each cured product was measured by using a type D durometer (trade name “GS-702G”, manufactured by TECLOCK Corporation).

Table 1 shows the light transmittance and D hardness immediately after curing as “initial transmittance [%]” and “initial hardness”, respectively.

Next, each cured product was irradiated with ultraviolet light having an intensity of 15 mW/cm² under an atmosphere at 120° C. for 500 h, and the light transmittance and the D hardness were measured in the same way. In addition, each cured product was exposed to a light-shielding atmosphere at 175° C. or 200° C. for 500 h, and the light transmittance and the D hardness were measured in the same way.

The light transmittance and the D hardness after irradiation with ultraviolet light under an atmosphere at 120° C. for 500 h were set to an “post-120° C. light resistance test (500 h) transmittance [%]” and “post-120° C. light resistance test (500 h) hardness”, respectively.

The light transmittance and D hardness after exposure under a light-shielding atmosphere at 170° C. for 500 h were set to a “post-175° C. heat resistance test (500 h) transmittance [%]” and “post-175° C. heat resistance test (500 h) hardness”; and the light transmittance and D hardness after exposure under a light-shielding atmosphere at 200° C. for 500 h were set to a “post-200° C. heat resistance test (500 h) transmittance [%]” and “post-200° C. heat resistance test (500 h) hardness”, respectively.

From the measured results, each transmittance maintenance rate and hardness change value were calculated by using the following equations: Post−120° C. light resistance test(500 h)transmittance maintenance rate [%]=(Post−120° C. light resistance test(500 h)transmittance [%]/Initial transmittance [%])×100; Post−175° C. heat resistance test(500 h)transmittance maintenance rate [%]=(Post−175° C. heat resistance test(500 h)transmittance [%]/Initial transmittance [%])×100; Post−200° C. heat resistance test(500 h)transmittance maintenance rate [%]=(Post−200° C. heat resistance test(500 h)transmittance [%]/Initial transmittance [%])×100; Post−120° C. light resistance test(500 h)hardness change value=Post−120° C. light resistance test(500 h)hardness−Initial hardness; Post−175° C. heat resistance test(500 h)hardness change value=Post−175° C. heat resistance test(500 h)hardness−Initial hardness; and Post−200° C. heat resistance test(500 h)hardness change value=Post−200° C. heat resistance test(500 h)hardness−Initial hardness.

Then, Table 1 shows “Post−120° C. light resistance test (500 h) transmittance maintenance rate”, “Post−175° C. heat resistance test (500 h) transmittance maintenance rate”, “Post−200° C. heat resistance test (500 h) transmittance maintenance rate”, “Post−120° C. light resistance test (500 h) hardness change value”, “Post−175° C. heat resistance test (500 h) hardness change value”, and “Post−200° C. heat resistance test (500 h) hardness change value”, respectively.

[Table 1]

TABLE 1 Example Example Example Example Example Example 1 2 3 4 5 6 Blended Component (A) Resin A-1 12 12 12 12 54 Components Resin A-2 60 60 60 60 Resin A-3 54 Component (B) Si-H monomer B-1 14 14 14 14 16 13 Si-H monomer B-2 1 1 1 1 1 Si-H monomer B-3 5 5 5 5 5 3 Component (C) Zirconium compound C-1 20 ppm 100 ppm 200 ppm Zirconium content (ppm) Zirconium compound C-2 20 ppm 20 ppm 20 ppm Zirconium content (ppm) Component (D) Pt catalyst (ppm)  1 ppm   1 ppm   1 ppm  1 ppm  2 ppm  1 ppm Component (E) Vinylsilalkylene E-1 8 8 8 8 Vinylsilalkylene E-2 25 25 Component (F) Silsesquioxane 1 1 1 1 4 Si-H/Si-Vi 1.16 1.16 1.16 1.16 0.94 1.03 a1/a2 of MTQ resin 2.00 2.00 2.00 2.00 0.08 3.86 Solid refractive index 1.49 1.49 1.49 1.49 1.49 1.49 Transmittance (450 nm) Initial transmittance [%] 91 90 91 90 90 91 Post-120° C. light resistance test (500 h) 100 99 100 100 98 Transmittance transmittance maintenance rate maintenance rate [%] Post-175° C. heat resistance test (500 h) 99 100 98 99 98 transmittance maintenance rate Post-200° C. heat resistance test (500 h) 97 transmittance maintenance rate Hardness Initial hardness 13 14 12 13 20 39 Hardness change value Post-120° C. light resistance test (500 h) 14 12 11 14 10 hardness change value Post-175° C. heat resistance test (500 h) 16 15 17 15 11 hardness change value Post-200° C. heat resistance test (500 h) 22 hardness change value Example Comparative Comparative Comparative Comparative 7 Example 1 Example 2 Example 3 Example 4 Blended Component (A) Resin A-1 54 12 54 54 Components Resin A-2 60 Resin A-3 54 Component (B) Si-H monomer B-1 13 14 16 13 13 Si-H monomer B-2 1 1 1 1 Si-H monomer B-3 3 5 5 3 3 Component (C) Zirconium compound C-1 Zirconium content (ppm) Zirconium compound C-2 20 ppm Zirconium content (ppm) Component (D) Pt catalyst (ppm) 5 ppm 1 ppm 2 ppm 1 ppm 5 ppm Component (E) Vinylsilalkylene E-1 8 Vinylsilalkylene E-2 25 25 25 25 Component (F) Silsesquioxane 4 1 4 4 Si-H/Si-Vi 1.03 1.16 0.94 1.03 1.03 a1/a2 of MTQ resin 3.86 2.00 0.08 3.86 3.86 Solid refractive index 1.49 1.49 1.49 1.49 1.49 Transmittance (450 nm) Initial transmittance [%] 91 91 90 91 91 Post-120° C. light resistance test (500 h) 100 98 Transmittance transmittance maintenance rate maintenance rate [%] Post-175° C. heat resistance test (500 h) 99 98 transmittance maintenance rate Post-200° C. heat resistance test (500 h) 93 97 93 transmittance maintenance rate Hardness Initial hardness 39 12 18 39 39 Hardness change value Post-120° C. light resistance test (500 h) 15 11 hardness change value Post-175° C. heat resistance test (500 h) 18 15 hardness change value Post-200° C. heat resistance test (500 h) 22 25 23 hardness change value

Variations of the present invention described above are added below.

[1] A curable resin composition comprising the following components (A), (B), (C), and (D):

-   -   (A): a polyorganosiloxane represented by the following average         unit formula (I):         (SiO_(4/2))_(a1)(R¹SiO_(3/2))_(a2)(R¹ ₂SiO_(2/2))_(a3)(R¹         ₃SiO_(1/2))_(a4)  (I)     -   wherein each R¹ is the same or different and is an alkyl group         having 1 to 10 carbon atoms (preferably a methyl group), an aryl         group having 6 to 14 carbon atoms (preferably a phenyl group),         an alkenyl group having 2 to 8 carbon atoms (preferably a vinyl         group), an alkoxy group having 1 to 10 carbon atoms (preferably         a methoxy group, an ethoxy group), or a hydroxyl group,     -   when a percentage of the alkyl group is X mol %, a percentage of         the aryl group is Y mol %, and a percentage of the alkenyl group         is Z mol % based on the total amount (100 mol %) of R¹, X is 50         to 98 mol %, Y is 1 to 50 mol %, and Z is 1 to 35 mol %, and     -   a1, a2, a3, and a4 are numbers satisfying a1>0, a2>0, a3≥0,         a4>0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1;     -   (B): a polyorganosiloxane represented by the following average         composition formula (II):         R² _(m)H_(n)SiO_([(4-m-n)/2])  (II)     -   wherein each R² is the same or different and is an alkyl group         having 1 to 10 carbon atoms (preferably a methyl group) or an         aryl group having 6 to 14 carbon atoms (preferably a phenyl         group), at least 2 hydrogen atoms are bonded to the silicon         atom, and m and n are numbers satisfying 0.7≤m≤2.1, 0.001≤n≤1.5,         and 0.8≤m+n≤3;     -   (C): a zirconium compound; and     -   (D): a hydrosilylation catalyst.

[2] The curable resin composition according to item [1], wherein X is 55 to 95 mol % (preferably 60 to 90 mol %).

[3] The curable resin composition according to item [1] or [2], wherein Y is 3 to 40 mol % (preferably 5 to 30 mol %).

[4] The curable resin composition according to any one of items [1] to [3], wherein Z is 2 to 25 mol % (preferably 3 to 15 mol %).

[5] The curable resin composition according to any one of items [1] to [4], wherein the component (A) is a polyorganosiloxane that has a weight-average molecular weight of not less than 500 and not more than 50000 in terms of polystyrene, has a molecular weight distribution of not less than 1 and not more than 4, and is a liquid or solid having a viscosity at 25° C. of 10 mPa·s or more.

[6] The curable resin composition according to any one of items [1] to [5], wherein a ratio of X to Y (X/Y) in the component (A) is 0.5 to 25 (preferably 1 to 20 and more preferably 2 to 15).

[7] The curable resin composition according to any one of items [1] to [6], wherein a1 is 0.01 to 0.8 (preferably 0.02 to 0.7 and more preferably 0.03 to 0.6).

[8] The curable resin composition according to any one of items [1] to [7], wherein a2 is 0.01 to 0.90 mol % (preferably 0.03 to 0.85 and more preferably 0.05 to 0.8).

[9] The curable resin composition according to any one of items [1] to [8], wherein a3 is 0 to 0.9 (preferably 0 to 0.6 and more preferably 0 to 0.3).

[10] The curable resin composition according to any one of items [1] to [9], wherein a4 is 0.01 to 0.9 (preferably 0.03 to 0.8 and more preferably 0.05 to 0.7).

[11] The curable resin composition according to any one of items [1] to [10], wherein a1/a2 is 0.02 to 8 (preferably 0.03 to 6, more preferably 0.1 to 5, more preferably 1 to 5, more preferably 1.5 to 5, and particularly preferably 2 to 5).

[12] The curable resin composition according to any one of items [1] to [11], wherein the weight-average molecular weight (Mw) of the component (A) is not less than 500 and not more than 50000 (preferably not less than 600 and not more than 40000, more preferably not less than 700 and not more than 20000, and particularly preferably not less than 1000 and not more than 10000).

[13] The curable resin composition according to any one of items [1] to [12], wherein the molecular weight distribution (Mw/Mn) of the component (A) is not less than 1 and not more than 4 (preferably 1 to 3.5, more preferably 1 to 3, and particularly preferably 1 to 2.5).

[14] The curable resin composition according to any one of items [1] to [13], wherein the viscosity at 25° C. of the component (A) is 10 mPa·s or more (preferably 100 mPa·s or more and more preferably 500 mPa·s or more).

[15] The curable resin composition according to any one of items [1] to [14], wherein the viscosity at 25° C. of the component (A) is 1000000 mPa·s or less (preferably 100000 mPa·s or less).

[16] The curable resin composition according to any one of items [1] to [15], wherein a content (amount blended) of the component (A) is 20 to 99 wt % (more preferably 40 to 97 wt % and still more preferably 50 to 95 wt %), based on the total amount (100 wt %) of the curable resin composition.

[17] The curable resin composition according to any one of items [1] to [16], wherein when a percentage of the alkyl group based on the total amount (100 mol %) of R² is X′ mol % in the component (B), X′ is 20 to 95 mol % (more preferably 30 to 93 mol % and still more preferably 40 to 90 mol %).

[18] The curable resin composition according to any one of items [1] to [17], wherein when a percentage of the aryl group based on the total amount (100 mol %) of R² is Y′ mol % in the component (B), Y′ is 1 to 80 mol % (preferably 3 to 60 mol % and more preferably 5 to 40 mol %).

[19] The curable resin composition according to any one of items [1] to [18], wherein when a percentage of the SiH group (a hydrosilyl group) based on the total amount (100 mol %) of R² is Z′ mol % in the component (B), Z′ is 2 to 70 mol % (preferably 5 to 60 mol % and more preferably 10 to 55 mol %).

[20] The curable resin composition according to any one of items [1] to [19], wherein a ratio of a content (X′) of the alkyl group to a content (Y′) of the aryl group (X′/Y′) in the component (B) is 1/100 to 100/1 (preferably 10/100 to 100/10 and more preferably 20/100 to 100/20).

[21] The curable resin composition according to any one of items [1] to [20], wherein m is 0.8 to 2.1 (preferably 1 to 2).

[22] The curable resin composition according to any one of items [1] to [21], wherein n is 0.01 to 1.25 (preferably 0.2 to 1).

[23] The curable resin composition according to any one of items [1] to [22], wherein m+n is 1 to 2.9 (preferably 1.5 to 2.8).

[24] The curable resin composition according to any one of items [1] to [23], wherein the component (B) comprises at least two (preferably 2 to 4 and more preferably 2) structural units (M-units) represented by (R^(2′) ₂HSiO_(1/2)) in a molecule where each R^(2′) is the same or different and is an alkyl group having 1 to 10 carbon atoms (preferably a methyl group) or an aryl group having 6 to 14 carbon atoms (preferably a phenyl group).

[25] The curable resin composition according to any one of items [1] to [24], wherein the form of component (B) is a liquid having a viscosity at 25° C. of 0.1 to 100000 mPa·s.

[26] The curable resin composition according to any one of items [1] to [25], wherein the component (B) comprises a polyorganosiloxane having at least two structural units (M-units) represented by (R^(2a) ₂HSiO_(1/2)), the polyorganosiloxane being represented by the following average unit formula (R^(2a)SiO_(3/2))_(c1)(R^(2a) ₂SiO_(2/2))_(c2)(R^(2a) ₃SiO_(1/2))_(c3)(SiO_(4/2))_(c4)(X⁵O_(1/2))_(c5)

-   -   wherein each R^(2a) is the same or different and is a hydrogen         atom, an alkyl group having 1 to 10 carbon atoms (preferably a         methyl group), or an aryl group having 6 to 14 carbon atoms         (preferably phenyl group),     -   X⁵ is a hydrogen atom or an alkyl group (preferably a methyl         group), and     -   c1 is 0 or a positive number, c2 is 0 or a positive number, c3         is 0 or a positive number, c4 is 0 or a positive number, c5 is 0         or a positive number, and (c1+c2+c3) is a positive number.

[27] The curable resin composition according to item [26], wherein a percentage of the hydrogen atom based on the total amount (100 mol %) of Rea is 1 to 70 mol %.

[28] The curable resin composition according to any one of items [1] to [27], wherein the component (B) is a straight-chain polyorganosiloxane having two or more hydrosilyl groups at both ends of the molecule.

[29] The curable resin composition according to item [28], wherein a percentage of the hydrogen atom (silicon-bonded hydrogen atom) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 1 to 70 mol %.

[30] The curable resin composition according to item [28] or [29], wherein a percentage of the alkyl group (in particular, methyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 20 to 95 mol % (preferably 40 to 95 mol %).

[31] The curable resin composition according to any one of items [28] to [30], wherein a percentage of the aryl group (in particular, phenyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 1 to 80 mol %.

[32] The curable resin composition according to any one of items [28] to [31], wherein the component (B) comprises a straight-chain polyorganosiloxane (hereinafter sometimes referred to as a component (B1)) represented by the following formula (II-1):

[Chem. 6]

-   -   wherein each R²¹ is the same or different and represents an         alkyl group having 1 to 10 carbon atoms (preferably a methyl         group) or an aryl group having 6 to 14 carbon atoms (preferably         a phenyl group),     -   x is an integer of 0 to 1000 (preferably an integer of 1 to         100).

[33] The curable resin composition according to item [32], wherein in the component (B), a content of the component (B1) is not less than 1 wt % and not more than 99 wt % (preferably not less than 10 wt % and not more than 50 wt %).

[34] The curable resin composition according to item [32] or [33], wherein the component (B1) is a liquid at 25° C.

[35] The curable resin composition according to any one of items [32] to [34], wherein the component (B1) has a viscosity at 25° C. of 10000 mPa·s or less (preferably 5000 mPa·s or less).

[36] The curable resin composition according to any one of items [32] to [35], wherein the component (B1) has a viscosity at 25° C. of 1 mPa·s or more (preferably 5 mPa·s or more).

[37] The curable resin composition according to any one of items [1] to [36], wherein the component (B) comprises, in a molecule, a branched-chain polyorganosiloxane having two or more M-units represented by (R2HSiO_(1/2)) and a siloxane unit (T-unit) represented by RSiO_(3/2) where R is an alkyl group having 1 to 10 carbon atoms (preferably a methyl group) or an aryl group having 6 to 14 carbon atoms (preferably a phenyl group).

[38] The curable resin composition according to item [37], wherein a percentage of the alkyl group (in particular, methyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 20 to 95 mol % (preferably 50 to 90 mol %).

[39] The curable resin composition according to item [37] or [38], wherein a percentage of the aryl group (in particular, phenyl group) based on the total amount (100 mol %) of groups bonded to the silicon atoms is 1 to 80 mol %.

[40] The curable resin composition according to any one of items [37] to [39], wherein the branched-chain polyorganosiloxane is represented by the average unit formula according to item [26] where the c1 is a positive number.

[41] The curable resin composition according to item [40], wherein c2/c1 is a number of 0 to 10.

[42] The curable resin composition according to item [40] or [41], wherein c3/c1 is a number of 0 to 0.5.

[43] The curable resin composition according to any one of items [40] to [42], wherein c4/(c1+c2+c3+c4) is a number of 0 to 0.3.

[44] The curable resin composition according to any one of items [40] to [43], wherein c5/(c1+c2+c3+c4) is a number of 0 to 0.4.

[45] The curable resin composition according to any one of items [37] to [44], wherein a weight-average molecular weight of the branched-chain polyorganosiloxane as measured by GPC in terms of standard polystyrene is 100 to 50000 (preferably 150 to 40000).

[46] The curable resin composition according to any one of items [1] to [45], wherein a weight-average molecular weight (Mw) of the component (B) is not less than 100 and not more than 50000 (preferably not less than 150 and not more than 40000, more preferably not less than 175 and not more than 20000, and particularly preferably not less than 200 and not more than 10000).

[47] The curable resin composition according to any one of items [1] to [46], wherein the component (B) has a molecular weight distribution (Mw/Mn) of not less than 1 and not more than 4 (preferably 1 to 3.5, more preferably 1 to 3, and particularly preferably 1 to 2.5).

[48] The curable resin composition according to any one of items [1] to [47], wherein the component (B) has a viscosity at 25° C. of 1 mPa·s or more (preferably 5 mPa·s or more).

[49] The curable resin composition according to any one of items [1] to [48], wherein the component (B) has a viscosity at 25° C. of 10000 mPa·s or less (preferably 5000 mPa·s or less).

[50] The curable resin composition according to any one of items [1] to [49], wherein the component (B) is at least one compound selected from the group consisting of 1,1,5,5-tetramethyl-3,3-diphenyltrisiloxane, 3-phenyl-1,1,3,5,5-pentamethyltrisiloxane, 1,1,3,3,5,5-hexamethyltrisiloxane, 1,1,3,3,5,5,7,7-octamethyltetrasiloxane, and 1,1,3,3,5,5,7,7,9,9-decamethylpentasiloxane.

[51] The curable resin composition according to any one of items [1] to [50], wherein the component (B) comprises one kind of polyorganosiloxane represented by the average composition formula (II), or comprises two or more different polyorganosiloxanes represented by the average composition formula (II).

[52] The curable resin composition according to any one of items [1] to [51], wherein the component (B) comprises at least one polyorganosiloxane represented by the average composition formula (II) where at least one of R² is an aryl group having 6 to 14 carbon atoms (preferably a phenyl group).

[53] The curable resin composition according to any one of items [1] to [52], wherein a content (amount blended) of the component (B) is 5 to 50 wt % (preferably 7 to 30 wt % and more preferably 10 to 25 wt %), based on the total amount (100 wt %) of the curable resin composition.

[54] The curable resin composition according to any one of items [1] to [53], wherein a content (amount blended) of the component (B) per 100 parts by weight of the component (A) is 1 to 200 parts by weight (preferably 5 to 100 parts by weight and more preferably 10 to 50 parts by weight).

[55] The curable resin composition according to any one of items [1] to [54], wherein the component (C) is at least one zirconium compound selected from the group consisting of an organic salt of zirconium, a zirconium alkoxide, a complex (complex salt) of zirconium, and an inorganic salt of zirconium (preferably at least one selected from the group consisting of an organic salt of zirconium, and a zirconium alkoxide).

[56] The curable resin composition according to item [55], wherein the organic salt of zirconium is an organic carboxylic acid salt (preferably a carboxylic acid salt having 1 to 20 carbon atoms, more preferably a carboxylic acid salt having 2 to 15 carbon atoms, more preferably a carboxylic acid salt having 4 to 12 carbon atoms, still more preferably a carboxylic acid salt having 5 to 10 carbon atoms, and particularly preferably a carboxylic acid salt having 8 carbon atoms).

[57] The curable resin composition according to item [56], wherein the organic carboxylic acid salt of zirconium is zirconium 2-ethylhexanoate.

[58] The curable resin composition according to any one of items [55] to [57], wherein the zirconium alkoxide is a zirconium alkoxide constituting of zirconium and an alcohol having 1 to 20 carbon atoms (preferably 1 to 6 carbon atoms) (preferably zirconium tetra-n-propoxide, zirconium tetraisopropoxide, zirconium tetrabutoxide, and the like).

[59] The curable resin composition according to any one of items [1] to [58], wherein a content of zirconium (in term of metal atom) in the component (C) is 0.1 to 300 ppm (preferably 0.5 to 250 ppm, more preferably 1 to 200 ppm), based on the total amount (10⁶ ppm) of the curable resin composition.

[60] The curable resin composition according to any one of items [1] to [59], wherein a content of zirconium (in term of metal atom) in the component (C) is 0.1 to 450 ppm (preferably 0.5 to 400 ppm, more preferably 1 to 350 ppm), based on the total amount (10⁶ ppm) of the component (A) and the component (B).

[61] The curable resin composition according to any one of items [1] to [60], wherein a content of the component (C) is 0.5 to 1800 ppm (preferably 1 to 1600 ppm, more preferably 3 to 1400 ppm), based on the total amount (10⁶ ppm) of the curable resin composition.

[62] The curable resin composition according to any one of items [1] to [61], wherein the component (D) is at least one compound selected from the group consisting of platinum-based catalysts (preferably, platinum fine powder, platinum black, platinum-supporting silica fine powder, platinum-supporting activated carbon, chloroplatinic acid, complexes of chloroplatinic acid and an alcohol, aldehyde, or ketone, olefin complexes of platinum, carbonyl complexes of platinum (preferably a platinum-carbonyl vinylmethyl complex), platinum-vinylmethylsiloxane complexes (preferably, a platinum-divinyltetramethyldisiloxane complex, a platinum-cyclovinylmethylsiloxane complex), platinum-phosphine complexes, and platinum-phosphite complexes), palladium-based catalysts (preferably, catalysts in which a palladium atom is contained instead of the platinum atom in each of the above platinum-based catalysts), and rhodium-based catalysts (preferably, catalysts in which a rhodium atom is contained instead of the platinum atom in each of the above platinum-based catalysts).

[63] The curable resin composition according to any one of items [1] to [62], wherein a content (amount blended) of the component (D) is 1×10⁻⁸ to 1×10⁻² mol (preferably 1×10⁻⁶ to 1×10⁻³ mol), based on the total amount (1 mol) of aliphatic carbon-carbon double bonds (in particular, an alkenyl group) contained in the curable resin composition.

[64] The curable resin composition according to item [63] or [64], wherein in the content (amount blended) of the component (D), an amount by weight of the platinum, palladium, or rhodium is an amount within a range of 0.01 to 1000 ppm (preferably an amount within a range of 0.1 to 500 ppm).

[65] The curable resin composition according to any one of items [1] to [64], further comprising the following component (E):

-   -   (E): a polyorganosiloxysilalkylene having a group containing one         or more aliphatic carbon-carbon unsaturated bonds (preferably a         vinyl group) in a molecule.

[66] The curable resin composition according to item [65], wherein the component (E) is a polyorganosiloxane having a group containing one or more aliphatic carbon-carbon unsaturated bonds in a molecule, and containing, as a main chain, a siloxane bond (—Si—O—Si—) and a bond represented by —Si—R^(A)—Si— (where R^(A) represents a divalent hydrocarbon group; hereinafter referred to as a “silalkylene bond”).

[67] The curable resin composition according to item [66], wherein the divalent hydrocarbon group (R^(A)) is a straight-chain or branched-chain alkylene group (e.g., a group represented by —[CH₂]_(t)— where t represents an integer of 1 or more) or a divalent alicyclic hydrocarbon group (preferably, a straight-chain or branched-chain alkylene group, particularly preferably an ethylene group).

[68] The curable resin composition according to any one of items [65] to [67], wherein a group bonded to the silicon atom other than groups containing the aliphatic carbon-carbon unsaturated bond of the component (E) is a hydrogen atom, a monovalent hydrocarbon group, or a monovalent heterocyclic group (preferably, a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a phenyl group, a naphthyl group, an anthryl group, a benzyl group, a phenethyl group, a pyridyl group, a furyl group, a thienyl group, a vinyl group, an allyl group, a styryl group (e.g., a p-styryl group), substituted hydrocarbon groups (e.g., a 2-(3,4-epoxycyclohexyl)ethyl group, a 3-glycidylpropyl group, a 3-methacryloxypropyl group, a 3-acryloxypropyl group, an N-2-(aminoethyl)-3-aminopropyl group, a 3-aminopropyl group, an N-phenyl-3-aminopropyl group, a 3-mercaptopropyl group, a 3-isocyanatepropyl group)).

[69] The curable resin composition according to any one of items [65] to [68], wherein the component (E) comprises a polyorganosiloxysilalkylene represented by the following average unit formula: (R⁴ ₂SiO_(2/2))_(d1)(R⁴ ₃SiO_(1/2))_(d2)(R⁴SiO_(3/2))_(d3)(SiO_(4/2))_(d4)(R^(A))_(d5)(X⁷O_(1/2))_(d6)

-   -   wherein each R⁴ is the same or different and is a hydrogen atom,         a monovalent hydrocarbon group, or a monovalent heterocyclic         group (preferably an alkyl group having 1 to 10 carbon atoms (in         particular, a methyl group), an aryl group having 4 to 14 carbon         atoms (in particular, a phenyl group), an alkenyl group having 2         to 8 carbon atoms (in particular, a vinyl group)), provided that         a portion of R⁴ is a group containing an aliphatic carbon-carbon         unsaturated bond (preferably an alkenyl group having 2 to 8         carbon atoms, in particular, a vinyl group) and a ratio of the         group is controlled to be one or more in a molecule; R^(A) is a         divalent hydrocarbon group (in particular, an ethylene group);         X⁷ is a hydrogen atom or a alkyl group (in particular, a         methyl); and d1 is a positive number (preferably 1 to 200), d2         is a positive number (preferably 1 to 200), d3 is 0 or a         positive number (preferably 1 to 10), d4 is 0 or a positive         number (preferably 0 to 5), d5 is a positive number (preferably         1 to 100), and d6 is 0 or a positive number.

[70] The curable resin composition according to item [69], wherein a percentage of the group containing an aliphatic carbon-carbon unsaturated bond based on the total amount (100 mol %) of R⁴ is 0.1 to 40 mol %.

[71] The curable resin composition according to item [69] or [70], wherein (d3+d4) is a positive number.

[72] The curable resin composition according to any one of items [65] to [71], wherein the component (E) comprises a polyorganosiloxysilalkylene having a structure represented by the following formula (IV-1):

[Chem. 7]

-   -   wherein each R⁴¹ is the same or different and is a hydrogen         atom, a monovalent hydrocarbon group, or a monovalent         heterocyclic group (preferably an alkyl group having 1 to 10         carbon atoms (in particular, a methyl group), an aryl group         having 4 to 14 carbon atoms (in particular, a phenyl group), an         alkenyl group having 2 to 8 carbon atoms (in particular, a vinyl         group), provided that at least one of R⁴¹ is a group containing         an aliphatic carbon-carbon unsaturated bond (preferably an         alkenyl group having 2 to 8 carbon atoms, in particular, a vinyl         group); R^(A) is a divalent hydrocarbon group (among them, a         C₂₋₄ alkylene group, in particular, an ethylene group); r1         represents an integer of 1 or more (preferably 1 to 100); r2         represents an integer of 0 or 1 or more (preferably 0 to 400);         r3 represents an integer of 0 or 1 or more (preferably 0 to 50);         r4 represents an integer of 0 or 1 or more (preferably 0 to 50);         and r5 represents an integer of 0 or 1 or more (preferably 0 to         50).

[73] The curable resin composition according to item [72], wherein the component (E) comprises a branched-chain polyorganosiloxysilalkylene where in the formula (IV-1), r1 represents an integer of 1 or more (preferably 1 to 100); r2 represents an integer of 1 or more (preferably 1 to 400); r3 represents an integer of 1 or more (preferably 1 to 50); r4 is 0; and r5 represents an integer of 1 or more (preferably 1 to 50).

[74] The curable resin composition according to item [72] or [73], wherein the component (E) comprises a straight-chain polyorganosiloxysilalkylene where in the formula (IV-1), r1 represents an integer of 1 or more (preferably 1 to 100); r2 represents an integer of 1 or more (preferably 1 to 400); r3 and r4 are 0; and r5 represents an integer of 1 or more (preferably 1 to 50).

[75] The curable resin composition according to any one of items [65] to [74], wherein the component (E) has a weight-average molecular weight (Mw) of not less than 500 and not more than 50000 (preferably not less than 700 and not more than 20000 and more preferably not less than 1000 and not more than 10000).

[76] The curable resin composition according to any one of items [65] to [75], wherein the component (E) has a molecular weight distribution (Mw/Mn) of not less than 1 and not more than 4 (preferably 1 to 3.5).

[77] The curable resin composition according to any one of items [65] to [76], wherein the component (E) has a viscosity at 25° C. of 100 mPa·s or more (preferably 500 mPa·s or more).

[78] The curable resin composition according to any one of items [65] to [77], wherein the component (E) has a viscosity at 25° C. of 50000 mPa·s or less (preferably 10000 mPa·s or less).

[79] The curable resin composition according to any one of items [65] to [78], wherein a content (amount blended) of the component (E) is 1 to 50 wt % (preferably 1 to 40 wt % and more preferably 5 to 30 wt %), based on the total amount (100 wt %) of the curable resin composition.

[80] The curable resin composition according to any one of items [65] to [79], wherein a content (amount blended) of the component (E) per 100 parts by weight of the component (A) is 1 to 200 parts by weight (preferably 5 to 100 parts by weight and more preferably 10 to 50 parts by weight).

[81] The curable resin composition according to any one of items [1] to [80] further comprising the following component (F):

-   -   (G): a silsesquioxane having one or more alkenyl groups         (preferably a vinyl group) and one or more aryl groups         (preferably a phenyl group) in a molecule.

[82] The curable resin composition according to item [81], wherein a group bonded to the silicon atom other than the alkenyl groups and the aryl groups in the molecule of component (F) is an alkyl group (in particular, methyl group).

[83] The curable resin composition according to item [81] or [82], wherein the percentage of the alkenyl group in the entire component (F) (100 wt %) is 1.0 to 20.0 wt % (preferably 1.5 to 15.0 wt %).

[84] The curable resin composition according to any one of items [81] to [83], wherein the percentage of the aryl group in the entire component (F) (100 wt %) is 1.0 to 50.0 wt % (preferably 5.0 to 25.0 wt %).

[85] The curable resin composition according to any one of items [82] to [84], wherein the percentage of the alkyl group in the entire component (F) (100 wt %) is 10.0 to 50.0 wt % (preferably 20.0 to 40.0 wt %).

[86] The curable resin composition according to any one of items [81] to [86], wherein the number of the alkenyl group in a molecule in the component (F) is 1 or more (preferably 2 to 50, and more preferably 2 to 30).

[87] The curable resin composition according to any one of items [81] to [86], wherein the component (F) has a weight-average molecular weight (Mw) of 100 to 800000 (preferably 200 to 100000, more preferably 300 to 10000, particularly preferably 500 to 8000, and most preferably 1700 to 7000).

[88] The curable resin composition according to any one of items [81] to [87], wherein the component (F) has a number average molecular weight (Mn) of 80 to 800000 (preferably 150 to 100000, more preferably 250 to 10000, particularly preferably 400 to 8000, and most preferably 1500 to 7000).

[89] The curable resin composition according to any one of items [81] to [88], wherein the component (F) has a molecular weight distribution (Mw/Mn) of 1.00 to 1.40 (preferably 1.35 or less (for example, 1.05 to 1.35), and more preferably 1.30 or less (for example, 1.10 to 1.30)).

[90] The curable resin composition according to any one of items [81] to [89], wherein the viscosity at 23° C. of the component (F) is 100 to 100000 mPa·s (preferably 500 to 10000 mPa·s, and more preferably 1000 to 8000 mPa·s).

[91] The curable resin composition according to any one of items [81] to [90], wherein the content (amount blended) of the component (F) is 0.05 to 50 parts by weight (preferably 0.1 to 45 parts by weight, and more preferably 0.2 to 40 parts by weight), based on a total amount of the component (A) and the component (B) of 100 parts by weight.

[92] The curable resin composition according to any one of items [81] to [91], wherein the content (amount blended) of the component (F) is 0.01 to 20 wt % (preferably 0.05 to 15 wt %, and more preferably 0.1 to 10 wt %), based on the curable resin composition (100 wt %).

[93] The curable resin composition according to any one of items [1] to [92], further comprising a silane coupling agent (G) (preferably an epoxy-containing silane coupling agent and particularly preferably 3-glycidoxypropyl trimethoxysilane).

[94] The curable resin composition according to item [93], wherein a content (amount blended) of the silane coupling agent (G) is 0.01 to 15 wt % (preferably 0.1 to 10 wt % and more preferably 0.5 to 5 wt %), based on the total amount (100 wt %) of the curable resin composition.

[95] The curable resin composition according to any one of items [1] to [94], wherein the composition (blending composition) is provided such that an amount of the hydrosilyl group (SiH group) contained in the component (B) per mol of the alkenyl group (including a group containing an aliphatic carbon-carbon double bond) present in the curable resin composition is not less than 0.1 mol and not more than 100 mol (preferably 0.3 to 50 mol, and more preferably 0.5 to 30 mol).

[96] The curable resin composition according to any one of items [1] to [95], wherein the curable resin composition has a viscosity at 23° C. of 300 to 20000 mPa·s (preferably 500 to 10000 mPa·s and more preferably 1000 to 8000 mPa·s).

[97] A cured product of the curable resin composition according to any one of items [1] to [96].

[98] The cured product according to item [97], wherein a refractive index at 589 nm thereof is not less than 1.46 and not more than 1.54 (preferably 1.465 to 1.535 and more preferably 1.47 to 1.53).

[99] The curable resin composition according to any one of items [1] to [96], wherein the curable resin composition is an encapsulating agent.

The curable resin composition according to any one of items [1] to [96], wherein the curable resin composition is a lens-forming resin composition.

A semiconductor device comprising a semiconductor element and an encapsulant that encapsulates the semiconductor element, wherein the encapsulant is a cured product of the curable resin composition according to item [99].

A semiconductor device comprising a semiconductor element and a lens, wherein the lens is a cured product of the curable resin composition according to item [100].

A semiconductor device comprising a semiconductor element, an encapsulant that encapsulates the semiconductor element, and a lens, wherein the encapsulant is a cured product of the curable resin composition according to item [99] and the lens is a cured product of the curable resin composition according to item [100].

The semiconductor device according to any one of items [101] to [103], wherein a refractive index at 589 nm of the cured product is not less than 1.46 and not more than 1.54 (preferably 1.465 to 1.535 and more preferably 1.47 to 1.53).

The semiconductor device according to any one of items [101] to [104], wherein the semiconductor device is an optical semiconductor device.

INDUSTRIAL APPLICABILITY

The curable resin compositions of the present invention can be suitably used as, in particular, materials for forming encapsulant for optical semiconductor elements (LED elements) and optical lens (encapsulating agents and lens-forming resin compositions) in optical semiconductor devices.

REFERENCE SIGNS LIST

-   -   100: Reflector (light-reflecting resin composition)     -   101: Metal wiring (electrode)     -   102: Optical semiconductor element     -   103: Bonding wire     -   104: Cured product (encapsulant) 

The invention claimed is:
 1. A curable resin composition comprising the following components (A), (B), (C), and (D): (A): a polyorganosiloxane represented by the following average unit formula (I): (SiO_(4/2))_(a1)(R¹SiO_(3/2))_(a2)(R¹ ₂SiO_(2/2))_(a3)(R¹ ₃SiO_(1/2))_(a4)  (I) wherein each R¹ is the same or different and is an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 14 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, or a hydroxyl group, when a percentage of the alkyl group is X mol %, a percentage of the aryl group is Y mol %, and a percentage of the alkenyl group is Z mol % based on the total amount (100 mol %) of R¹, X is 50 to 98 mol %, Y is 1 to 50 mol %, and Z is 1 to 35 mol %, and a1, a2, a3, and a4 are numbers satisfying a1>0, a2>0, a3≥0, a4>0, 0.01≤a1/a2≤10, and a1+a2+a3+a4=1; (B): a polyorganosiloxane represented by the following average composition formula (II): R² _(m)H_(n)SiO_([(4-m-n)/2])  (II) wherein each R² is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms, at least 2 hydrogen atoms are bonded to the silicon atom, and m and n are numbers satisfying 0.7≤m≤2.1, 0.001≤n≤1.5, and 0.8≤m+n≤3_(;) (C): a zirconium compound; and (D): a hydrosilylation catalyst.
 2. The curable resin composition according to claim 1, wherein the component (A) is a polyorganosiloxane that has a weight-average molecular weight of not less than 500 and not more than 50000 in terms of polystyrene, has a molecular weight distribution of not less than 1 and not more than 4, and is a liquid or solid having a viscosity at 25° C. of 10 mPa·s or more.
 3. The curable resin composition according to claim 1, wherein a ratio of X to Y (X/Y) in the component (A) is 0.5 to
 25. 4. The curable resin composition according to claim 1, wherein a content of zirconium (in term of metal atom) in the component (C) is 0.1 to 300 ppm, based on the total amount (10⁶ ppm) of the curable resin composition.
 5. The curable resin composition according to claim 1, further comprising the following component (E): (E): a polyorganosiloxysilalkylene having a group containing one or more aliphatic carbon-carbon unsaturated bonds in a molecule.
 6. The curable resin composition according to claim 1, further comprising the following component (F): (F): a silsesquioxane having one or more alkenyl groups and one or more aryl groups in a molecule.
 7. The curable resin composition according to claim 1, wherein the component (B) comprises at least two structural units represented by (R^(2′) ₂HSiO_(1/2)) where each R^(2′) is the same or different and is an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms.
 8. The curable resin composition according to claim 1, wherein the component (B) comprises a component (B1) at a content of not less than 1 wt % and not more than 99 wt %, the component (B1) being represented by the following formula (II-1): [Chem. 1]

wherein each R²¹ is the same or different and represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 14 carbon atoms, and x represents an integer of 0 to 1000, and the component (B1) being a liquid having a viscosity at 25° C. of 10000 mPa·s or less.
 9. The curable resin composition according to claim 1, wherein the component (B) comprises one kind of polyorganosiloxane represented by the average composition formula (II), or comprises two or more different polyorganosiloxanes represented by the average composition formula (II).
 10. The curable resin composition according to claim 1, wherein the component (B) comprises at least one polyorganosiloxane represented by the average composition formula (II) where at least one of R² is an aryl group having 6 to 14 carbon atoms.
 11. The curable resin composition according to claim 1, further comprising a silane coupling agent (G).
 12. A cured product of the curable resin composition according to claim
 1. 13. The cured product according to claim 12, wherein a refractive index at 589 nm thereof is not less than 1.46 and not more than 1.54.
 14. The curable resin composition according to claim 1, wherein the curable resin composition is an encapsulating agent.
 15. A semiconductor device comprising a semiconductor element and an encapsulant that encapsulates the semiconductor element, wherein the encapsulant is a cured product of the curable resin composition according to claim
 14. 16. The semiconductor device according to claim 15, wherein a refractive index at 589 nm of the cured product is not less than 1.46 and not more than 1.54.
 17. The semiconductor device according to claim 15, wherein the semiconductor device is an optical semiconductor device.
 18. The curable resin composition according to claim 1, wherein the curable resin composition is a lens-forming resin composition.
 19. A semiconductor device comprising a semiconductor element and a lens, wherein the lens is a cured product of the curable resin composition according to claim
 18. 20. A semiconductor device comprising a semiconductor element, an encapsulant that encapsulates the semiconductor element, and a lens, wherein the encapsulant comprises a cured product of the curable resin composition according to claim 1 and the lens comprises a cured product of the curable resin composition. 